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914World.com _ 914World Garage _ Weber 44 IDF's - keep - or find original d-jet?
Posted by: Gatornapper Oct 9 2017, 04:03 PM
Questions re: Weber 44 IDF carbs:
1. Is anyone running these on a stock engine, and if so, how do they perform? National Carburetors kit for stock engines is 34 ICT's, lightly modified 40 IDF's, and only 44's on heavily modified engines.
2. What problems do you introduce using 44's? other than dumping too much fuel in the engine......
3. Venturi's are 45mm, someone pointed out that one should use 40mm venturi's - is that with a stock engine?
4. Anyone run 44's and then convert back to EFI? How did that go? Labor cost?
TIA,
GN
Posted by: BillC Oct 9 2017, 04:36 PM
It'll be more work than just slapping on a set of carbs, but I think you'll be happier in the long run if you install the original D-Jet setup. Plus, the car will be worth more once it's all done.
If you're going to stick with carbs, the 44s are too big for a stock engine. The 40s might work for a 2.0, but might be too big if you still have the stock cam. The 34s will give you the best drivability around town and fuel mileage, but you might sacrifice a little on the top end on a 2.0.
Posted by: Gatornapper Oct 9 2017, 05:31 PM
Bill -
I restore old motorcycles so I know the more original, the more the value....
The 44's are on the car now & I'm rebuilding them. My good friend in whose barn the car has sit for 10 years said the car was running perfectly when it was driven in the barn and he had been riding in it with the PO (another friend of his) that day.
I'm now thinking I want to flip the car ASAP.
Will the car run ok with the 44's? 10mpg?
And where would I start looking for the original D-Jet setup and how do I know I'm getting a full, properly working system? Reliable sources?
Thanks!
GN
It'll be more work than just slapping on a set of carbs, but I think you'll be happier in the long run if you install the original D-Jet setup. Plus, the car will be worth more once it's all done.
If you're going to stick with carbs, the 44s are too big for a stock engine. The 40s might work for a 2.0, but might be too big if you still have the stock cam. The 34s will give you the best drivability around town and fuel mileage, but you might sacrifice a little on the top end on a 2.0.
Posted by: Gatornapper Oct 9 2017, 06:21 PM
The PO told me the Weber's didn't produce any more power, but made the engine a lot more responsive......
GN
Posted by: Gatornapper Oct 9 2017, 06:23 PM
Don't you have to pull the engine to change the intake manifold?
Or can it be done from on top? Doesn't seem possible from looking at things.....
GN
Posted by: Gatornapper Oct 9 2017, 07:18 PM
A long-term member here has a complete D-Jet system in his garage for $250 - think I'd better grab it.........
GN
Posted by: thelogo Oct 9 2017, 10:27 PM
Yeh the 44s are technically too big but
D-jet is not supported by me personally cause it is waaayyyy
To complex or spookey weird
Carbs are simple , me i just trust them alot more
But they constantly want to go wide open throttle
D-jet never gos wide open throttle 
Where is the go to 914 world , individual throttle body
Fuel injection conversion , that i would buy .
But carbs till then
Posted by: Gatornapper Oct 10 2017, 04:39 AM
????? So why won't the D-Jet go full throttle?????
GN
Yeh the 44s are technically too big but
D-jet is not supported by me personally cause it is waaayyyy
To complex or spookey weird
Carbs are simple , me i just trust them alot more
But they constantly want to go wide open throttle
D-jet never gos wide open throttle Where is the go to 914 world , individual throttle body
Fuel injection conversion , that i would buy .
But carbs till then
Posted by: Gatornapper Oct 10 2017, 05:56 AM
Logo -
Options:
1. So, If I put a cam in the engine and high-performance exhaust on, the 44's would work?
What would that do to the value of the car? Money in, value down it seems.
2. Buy the kit for the 34 carbs, easy install, sell the 44's (they'll be looking like new after my rebuild) for the cost of the 34's. Simple, easy, little to no cost - engine should run great.
3. Buy the D-Jet system from an "original" member here ('04), go through the hassle of learning the system (experienced with old Volvo EFI systems), finding & replacing possible defective parts, sell the 44's for a profit.
Decisions, decisions, decisions. #2 is the most simple for me.
On #3, how to I ensure that the D-Jet system I purchase is good? Lots of parts could be defective, including the difficult-to-find ECU.
GN
[quote name='thelogo' post='2536095' date='Oct 9 2017, 10:27 PM']
Yeh the 44s are technically too big but
D-jet is not supported by me personally cause it is waaayyyy
To complex or spookey weird
Carbs are simple , me i just trust them alot more
But they constantly want to go wide open throttle
D-jet never gos wide open throttle
Where is the go to 914 world , individual throttle body
Fuel injection conversion , that i would buy .
But carbs till then
[/quote]
[/quote]
Posted by: BeatNavy Oct 10 2017, 06:39 AM
If you don't want to learn D-Jet, do what you know. There will be a learning curve, and yes, the D-Jet components will be in varying states of usability and repair. I'd recommend buying a new wiring harness from Bowlsby if you do go that route, but that's just my thought.
Part of my personal enjoyment with these cars is challenging myself and learning new things, but that's not an interest for everyone. Some people just want it to work and drive it.
Your car, your call.
Posted by: The Cabinetmaker Oct 10 2017, 06:44 AM
D jet won't go full throttle? 
Posted by: BeatNavy Oct 10 2017, 07:10 AM
D jet won't go full throttle?
Yeah, I didn't understand that either
Posted by: The Cabinetmaker Oct 10 2017, 08:32 AM
Just
Another
Useless
Post?
Posted by: Gatornapper Oct 10 2017, 01:40 PM
BN -
Normally I LOVE mechanical/electrical challenges, and all things being normal, I'd really enjoy doing this.
But right now I am (at 72) totally overloaded with technical challenges flipping a fairly expensive house with a lot of issues and fighting a dozen other alligators (someone ask me where "Gatornapper" came from sometime - name given to me by a major US newspaper.....in 1965), and the last thing I need is another challenge.
I only bought this car because of all the work IT DIDN'T NEED, but have worked on enough old vehicles (I restore old motorcycles) to know there would be plenty of hidden issues to deal with. I just don't need to add more......
So how much is a new wiring harness?
I know it's inevitable that "components will be in varying states of usability and repair." - and some parts are getting very hard to find.
I think I have a plan - will post it next.
Thanks man!
GN
If you don't want to learn D-Jet, do what you know. There will be a learning curve, and yes, the D-Jet components will be in varying states of usability and repair. I'd recommend buying a new wiring harness from Bowlsby if you do go that route, but that's just my thought.
Part of my personal enjoyment with these cars is challenging myself and learning new things, but that's not an interest for everyone. Some people just want it to work and drive it.
Your car, your call.
Posted by: Gatornapper Oct 10 2017, 01:54 PM
Ok, here's the plan:
1. Purchase D-Jet unit (complete) from bigkensteele;
2. Finish rebuilding existing Weber 44's, see how car runs. If I can tune carbs where car runs well (or find a tuner who can), get car in top mechanical and beauty shape and sell it & the D-Jet system with it; a strong position.
NOTE: Local Porsche dealer service manager remembered every detail about this car and the carbs being put on. Said it was running perfectly when service was finished installing the carbs & there were no issues then.
3. If Weber 44's cannot be tuned so car runs well, I will pull them and install the D-Jet system. Invariably there will be issues, problems to solve. Big Ken said car was not running well when he pulled the system from his '76 2.0. If I can get car running well with D-Jet installed, I'll sell it that way and come out ahead - I'll sell the Weber 44's for a good price as I'll have them like new & they only have 2,000 miles on them. An even stronger position.
4. If a good Porsche mechanic cannot get the D-Jet system running well, I'll purchase and install the Weber 34 ICT kit, get car running well (should be very easy), and sell car WITH the D-Jet kit so new owner can install it if he/she wants to. I'll sell the almost-new, rebuilt Weber 44's for a good price. Not a bad fall-back position.
Hey, TEAM!......
Sound like a plan?
GN
PS: Wife (wonderful, beautiful) normally lets me do what I want vehicle-wise. But she has strongly communicated she wants only one Porsche in the family.
Posted by: The Cabinetmaker Oct 10 2017, 02:13 PM
So, you bought a 914 to flip and make money? I wish you luck sir.
Posted by: Dave_Darling Oct 10 2017, 03:00 PM
If the cam has been changed out for a carb-friendly one, you'll never get the D-jet to work right.
Sir Andy got his car to work OK with 44s, but he swapped in smaller venturis. I don't remember the size, possibly 36es?
The larger carbs on the smaller engine will give you a week vacuum to pull fuel into the air stream. Mixture quality will suffer at low RPMs, and low-end torque and drivability will probably be worse. It will be able to wind way up at WOT, but the stock cam and heads limit your useable RPM range anyway.
That said, they can be made to work. But 40s are generally preferred on 914 motors.
As Rob C. said--if you know carbs and don't want to learn D-jet, stick with carbs. Use your best judgement on what size will work for you.
If you're selling the car, it's usually best to do as little as possible to it. You almost never get back the full cost of work done to a car when you sell it.
--DD
Posted by: Gatornapper Oct 10 2017, 03:47 PM
Actually I bought it to keep it. And to enjoy driving it.
Very recent changes in our financial situation dictate that we need the cash.
Ever had that happen? If not, you are young.......
GN
So, you bought a 914 to flip and make money? I wish you luck sir.
Posted by: The Cabinetmaker Oct 10 2017, 05:02 PM
Hmmm, my profile says I was born in 1948, so I guess I'm not very young
Posted by: Gatornapper Oct 10 2017, 05:05 PM
ALL NEW INFO!
My expert friend in GA advised me to call Pierce Manifolds in CA as they are one of the top Weber carb experts in the nation. Had a great long talk with Steve who blew me away with his knowledge of Weber setups with the 2.0 engine.
Findings:
1. The existing setup with the 44's with 44mm venturi's would work fine on the stock 2.0 engine, producing this performance: no low-end torque, great performance between 4500 and 6500 rpm. I.e., racing. As the PO used to race 911's, he probably DID know what he was doing and wanted to get the best performance out of the stock 2.0 engine, while sacrificing all low-end/street-drivability performance. Low-end and mid-range torque would both be weak.
2. The 44 IDF carbs would perform perfectly fine for regular street driving, up to 5000 rpm, using 32mm venturi's, providing good mid-range torque.
3. I had him run his calculations (was he using a calculator? Sounded like it! Certainly wasn't a computer as he was doing square roots, etc.!) for 34mm, 36mm, and 40mm venturi's. For each one he would give me the torque levels at various rpm.
4. All venturi's larger than 32mm suffered a loss of mid-range torque, with the gain of high rpm torque. After listening to all the numbers he ran by me, it was clear that even the 34mm venturi's would require almost constant driving above 4500 rpm - which is not - to me - normal driving. Not on a 41 year old Volkswagen engine with 60k miles on it.
So I ordered a set of 32mm carbs and cannot wait to see how they run. If all is as I expect it will go, I'll leave the 44's on the car and let the next owner decide on the D-Jet system.
If I feel the higher rpm performance is lacking, I can easily try 34mm venturi's - for just $60.......
GN
Posted by: Gatornapper Oct 10 2017, 05:33 PM
Dave -
Thought I posted a Thank You for your feedback earlier, but don't see it - so - Thank you.
Everything you noted was confirmed today in my call with Pierce Manifolds, only in more detail.
I do remember reading the same about 36mm venturi's on another thread here after a search.
I do know carbs but also have experience with EFI systems - I am an electrical engineer with 30 years in computers. But I hear horror stories on the D-Jet systems, constant problems, parts hard to find, etc. I am used to non-stop "fix-or-repair-daily" on my '70's Triumph motorcycles (I ride them all regularly), but don't need that in a car. Actually, all my old Trumpies are very reliable as I've had them long enough to shake down almost all issues....they all usually start on 1 kick, hot or cold.....who needs electric start?
GN
If the cam has been changed out for a carb-friendly one, you'll never get the D-jet to work right.
Sir Andy got his car to work OK with 44s, but he swapped in smaller venturis. I don't remember the size, possibly 36es?
The larger carbs on the smaller engine will give you a week vacuum to pull fuel into the air stream. Mixture quality will suffer at low RPMs, and low-end torque and drivability will probably be worse. It will be able to wind way up at WOT, but the stock cam and heads limit your useable RPM range anyway.
That said, they can be made to work. But 40s are generally preferred on 914 motors.
As Rob C. said--if you know carbs and don't want to learn D-jet, stick with carbs. Use your best judgement on what size will work for you.
If you're selling the car, it's usually best to do as little as possible to it. You almost never get back the full cost of work done to a car when you sell it.
--DD
Posted by: injunmort Oct 10 2017, 05:36 PM
well, you have all the answers, good luck.
Posted by: Gatornapper Oct 10 2017, 05:48 PM
Rob -
One of my fav things is diagnosing and fixing things. And learning new things.
My problem right now is time - too many projects going at once, one that keeps pulling my head underwater.
How much is the new harness? Why are the harnesses so problematic? Typically it's not the wiring, but the terminations in connectors. Are the connectors Bosch?
Thanks,
GN
If you don't want to learn D-Jet, do what you know. There will be a learning curve, and yes, the D-Jet components will be in varying states of usability and repair. I'd recommend buying a new wiring harness from Bowlsby if you do go that route, but that's just my thought.
Part of my personal enjoyment with these cars is challenging myself and learning new things, but that's not an interest for everyone. Some people just want it to work and drive it.
Your car, your call.
Posted by: Gatornapper Oct 10 2017, 05:50 PM
NO! DO NOT have all the answers. Never have, never will.
I do have a plan.....huge difference......
Tomorrow new information/data may come - new answers - and bring about a new plan.
Your input Mort, has all been greatly appreciated.
GN
well, you have all the answers, good luck.
Posted by: BeatNavy Oct 10 2017, 05:56 PM
Here's the link to Jeff's page: http://bowlsby.net/914/WiringHarnesses/
The harnesses are not cheap (depending on your definition of cheap), but they do give you piece of mind and help eliminate lots of troubleshooting variables. Once you get your hands on a harness that's over 40 years old and spent most of its life in a hot engine bay, you'll understand why. The old wiring harnesses get very brittle and "crunchy."
Having said that, if you're not looking long term, it may not be worth the investment. Overall, I agree with DD at this point. I'm fully confident you could figure out the D-Jet system, and we can provide lots of help, but based on the way you described your plans and situation I'd probably recommend sticking with getting the right carbs working properly.
Posted by: Gatornapper Oct 10 2017, 06:04 PM
Cabinetmaker -
Long discussion with good friend resulted in a change in strategy on a major investment that just may allow me to keep the 914.
I sure hope so.
A very good friend of mine for 44 years.... http://www.harrisonhigginsinc.com/
About 20 years ago he was asked to head up Colonial Williamsburg's Reproductions unit, his work is in the top executive offices of major NY banks (and my bedroom), has taught in a major university. His son now runs his business. But Harrison (elder) is still in the shop almost every day.
GN
PS: from where I sit, you are young. But old enough to know what I meant for sure....
So, you bought a 914 to flip and make money? I wish you luck sir.
Posted by: Gatornapper Oct 10 2017, 06:22 PM
Rob -
Again - thanks.
I've built complex wiring harnesses myself. Wouldn't attempt this one as I have no source for the connectors nor the tools to do the wire crimping/terminating.
Think I'll evaluate and test the harness that I get from Ken and then decide.
Great source for me to study here:
http://bowlsby.net/914/Classic/zTN_Man06.pdf
I'm thinking now if I can keep the car to study the system thoroughly until I know it pretty well, then maybe this winter test all the components, replace questionable ones, and look at installing before spring.
GN
PS: One son says, "Beat Navy!" Another says, "Beat Army!" One son says, "Beat UVA!" A daughter says, "Beat VA Tech!" But we all love one another anyway.....
Here's the link to Jeff's page: http://bowlsby.net/914/WiringHarnesses/
The harnesses are not cheap (depending on your definition of cheap), but they do give you piece of mind and help eliminate lots of troubleshooting variables. Once you get your hands on a harness that's over 40 years old and spent most of its life in a hot engine bay, you'll understand why. The old wiring harnesses get very brittle and "crunchy."
Having said that, if you're not looking long term, it may not be worth the investment. Overall, I agree with DD at this point. I'm fully confident you could figure out the D-Jet system, and we can provide lots of help, but based on the way you described your plans and situation I'd probably recommend sticking with getting the right carbs working properly.
Posted by: BeatNavy Oct 10 2017, 06:30 PM
Here's another resource for you: https://members.rennlist.com/pbanders/djetparts.htm
I've read that page probably 100 times or more.
I've got a son who says "Beat UVA" and a daughter that hopes to say the same in a few months. And another daughter who should be saying "I need a job. Hire me."
Posted by: Gatornapper Oct 10 2017, 07:38 PM
WOW! What a gold mine! I can pre-test all the components before installing the system!
PRICELESS!
I can also see issues ahead I need to address: return line on tank sealed off, and more.
Car has new Electronic Ignition - need to open distributor to see what's inside - points? Or electronic? wonder if I can use EI with the FI.....?????
Lots of questions.....
GN
PS: We are a VA Tech family, and it was really hard on me when my daughter decided to go to UVA, but she graduated Phi Beta Kappa with distinction, so we are grateful. Have graduates of VA Tech, UVA, Liberty, Univ. of Richmond and ODU - all who put themselves through. Daddy told all 8 kids, "No way Dad will ever make enough to put 8 kids thru college, and wouldn't be fair to pay for some and not others - so here's the deal: you earn your own way through college and Daddy will buy you a nice car!" It worked. I bought 5 cars, they have 8 degrees among them. 3 chose no college but are each very successful in their careers. Family pic on Thread "What the Heck do you look like?"
Here's another resource for you: https://members.rennlist.com/pbanders/djetparts.htm
I've read that page probably 100 times or more.
I've got a son who says "Beat UVA" and a daughter that hopes to say the same in a few months. And another daughter who should be saying "I need a job. Hire me."
Posted by: Dave_Darling Oct 10 2017, 08:52 PM
If you like staring at analog circuits, you can download the circuit diagrams for the D-jet ECU from Brad Anders' page there. The diagrams were drawn up by Frank Kerfoot, who I believe was a sparky at Bell Labs at the time. I was able to get ahold of a copy and scan them, and Brad volunteered to try to make sense out of them. (Better anyone else than me!!!)
The D-jet is electronic, but just barely. Everything is analog, and the basic injection pulse width (time the injector is open) is determined by the inductive coupling between two coils of wire, moderated by a metal rod that is physically moved by air pressure.... It's massively funky to someone who is more used to 1s and 0s!
Anyway, sounds like you have a plan, which is more than half the battle.
--DD
Posted by: Gatornapper Oct 11 2017, 01:21 AM
Dave -
Ha! Like I'm gonna want to dig into analog circuitry before I even understand how the system works? No way!
But very kind and gracious of you - thank you so much!
Even in the '70's when I was fiddling with Volvo's analog ECU, I didn't bother getting into their analog circuitry - grasping all the I/O devices was enough! And that will be enough for me on the D-Jet system as well.
While I am anal/retentive (boy, haven't heard that one in a long time), I am not so much so that I'd want to dig into analog circuitry.
But your feedback is indeed greatly appreciated!
GN
If you like staring at analog circuits, you can download the circuit diagrams for the D-jet ECU from Brad Anders' page there. The diagrams were drawn up by Frank Kerfoot, who I believe was a sparky at Bell Labs at the time. I was able to get ahold of a copy and scan them, and Brad volunteered to try to make sense out of them. (Better anyone else than me!!!)
The D-jet is electronic, but just barely. Everything is analog, and the basic injection pulse width (time the injector is open) is determined by the inductive coupling between two coils of wire, moderated by a metal rod that is physically moved by air pressure.... It's massively funky to someone who is more used to 1s and 0s!
Anyway, sounds like you have a plan, which is more than half the battle.
--DD
Posted by: Gatornapper Oct 11 2017, 03:32 PM
Got a call from my good friend in whose barn the 914 was parked for about 12 years. I brought him up to speed on how things are going with the car, and the whole issue of the carbs.
He re-affirmed to me today what he had told me earlier: he had been riding in the car through that day with the PO (also a good friend of his) and he said he was really impressed with how strong the engine was for a 2 liter. He affirmed again how well it ran.
SO, I am going to initially install the 44 IDF Weber's with the 44mm venturi's.
I gotta find out what he is talking about. And if the Weber expert at Pierce Manifolds in CA was correct about no mid-range torque.
Who knows? If it runs great mid-range, I just may return the 32mm venturi's.
On a related issue, Ken in Cinci (bigkensteele) sent me a pic of the D-Jet system and I was blown away at the tiny throat on the throttle body. Looked like 28mm. How can that thing breathe? And the air intake nozzle is even smaller!
Heck, the throat on the Amal carb on my '71 Triumph Trophy 500 is 26mm!
So anyone tell me the diameter of the throttle body throat on the D-Jet?
TIA,
GN
Posted by: The Cabinetmaker Oct 11 2017, 03:39 PM
Closer to 50mm
Posted by: Gatornapper Oct 11 2017, 03:55 PM
More better. Hard to tell from the pic.
Thanks.....
Closer to 50mm
Posted by: mgphoto Oct 11 2017, 04:01 PM
FYI Volvos 142 2.0 E 144 2.0E 164 3.0E 1800 2.0E 1800 2.0E S all D-Jet.
Posted by: Gatornapper Oct 11 2017, 05:18 PM
So the Weber 44's with 44mm venturi's are going to allow 3 1/2 times the air into the engine at WOT....and at least 3 1/2 times the fuel.......5 mpg?????
This will be interesting. Waiting on my Weber Technical Manual.....
More better. Hard to tell from the pic.
Thanks.....
Closer to 50mm
Posted by: injunmort Oct 11 2017, 05:41 PM
dude, you are all over the map. get the car running with the 44's. thats whats on hand. the fi works better, period. as i said before, the 44's will work decently, with compromises. the d-jet is better. since you are trying to flip for paymax, running with carbs is better than not running with anything. stock d-jet, running car is worth more than non running carbs or running with carbs that just need "a cleaning. get the car running first. then, you can ponder the theoreticals. like, are yellow cars really faster. btw, i have a very fast, running and driving yellow 914. have i mentioned that?
Posted by: Gatornapper Oct 11 2017, 06:31 PM
Mort -
Am I all over the map? Not quite - but I get your drift. And I have very good reason.
I have been very successful in life and one reason is I research things to death before I move. And if circumstances demand that I zig when I'm in the middle of a zag - I do that well.
I keep getting new information in my research - and that's why I make changes in my plans.
I am on hold while I wait for parts, Weber Tech Manual, and much more. I won't even be able to start the car for several weeks. I've been rebuilding carbs for over 50 years. When I'm done, they will be as good as new. The time to ponder the theoreticals is now, not when I have all the parts.
I think if you track every change I've made in my plan, each one is a logical and reasonable result of new information. Just this week I've received three or four bit of information that logically suggested a change in direction.
"Get the car running with the 44's" - of course. But if it truly was running strong when parked, why not try the existing 44mm venturi's at first? My good friend who kept the car but didn't own it would not lie to me. The car was running strong when parked.
I HOPE to keep the car and drive it regularly. I didn't buy it to flip it. I bought it as a non-depreciating investment that I could enjoy.
Future cash-flow situations will dictate whether I keep or sell the car. If I sell it, the EFI will go on it for sure. I currently have a huge investment in a project that is taking most of my time and most of my discretionary funds - so it has my attention.
I really won't even have time to spend on the car for a month or more.
In the meantime, pondering the theoreticals is what I'm going to do.
Tell me more please about your fast yellow 914....or send me link to that info.
I love learning from others.......and while I have 50 years wrenching vehicles, machinery, tractors, etc. I am very ignorant about 914's - which are truly unique animals.
Your thoughts are always appreciated.
GN
dude, you are all over the map. get the car running with the 44's. thats whats on hand. the fi works better, period. as i said before, the 44's will work decently, with compromises. the d-jet is better. since you are trying to flip for paymax, running with carbs is better than not running with anything. stock d-jet, running car is worth more than non running carbs or running with carbs that just need "a cleaning. get the car running first. then, you can ponder the theoreticals. like, are yellow cars really faster. btw, i have a very fast, running and driving yellow 914. have i mentioned that?
Posted by: Justinp71 Oct 11 2017, 06:49 PM
I personally like carbs on these old cars because they are very reliable and simple (although sometimes takes awhile to get it tuned just right), if I was doing an engine swap with a modern FI though I'd probably keep it. I have no experience with D-jet, only with CIS. I was super happy when I ditched my CIS and put on webbers. dont forget to change your fuel pump or use a reliable regulator that can take FI pressures.
Posted by: Gatornapper Oct 11 2017, 07:01 PM
Thanks Justin.
Looks like carbs vs. FI on 914's is like Dems and Repubs.....about a 50/50 split on which is best, each side arguing strongly why they believe what they believe.
Cannot count all who have told me to avoid the D-Jet system, that it's non-stop problems and issues and not that good as it was really a Gen I EFI. My service mgr. at the local Porsche dealer strongly advised me to stick with carbs, for both performance and reliability. He doesn't see many 914's, but most of those he does see have problems with the FI.
I will get Ken's D-Jet system tho so that if I have to sell the car, I can restore it to original - but I'm sure it will need a lot of new pieces, like the manifold pressure sensor, harness, etc.
Get a carb set right, and forget it!
And for sure I want more power than the D-Jet can supply on a stock engine.....
Oh, I have both the original fuel pump that was on the D-Jet AND a new Carter 3.5psi fuel pump & filter for the carbs. Carter is in the car now.
GN
I personally like carbs on these old cars because they are very reliable (although sometimes takes awhile to get it tuned just right), if I was doing an engine swap with a modern FI though I'd probably keep it. I have no experience with D-jet, only with CIS. I was super happy when I ditched my CIS and put on webbers. dont forget to change your fuel pump or use a reliable regulator that can take FI pressures.
Posted by: injunmort Oct 11 2017, 08:11 PM
have at it bro. but a statement like you want more power than d-jet is capable of is moronic. you can get more power, less longeivty out of a 2.0l type 4, but d-jet is not the limiting factor. displacement, compression ratios, flow, etc, are. d-jet works for up to 2500cc without cam or ecu mods. so, flow your head, deck your cylinders, do cams, and run 44's. oh, wait, then its not a stock 2.0l type 4, then,is it. no, now you are in raby territory. great engines with the r&d to back up, but at $20k you get what you pay for. whoever told you 44's are a better delivery fuel system is an idiot, ever though they dont work on allot of 914's.
Posted by: kgruen2 Oct 15 2017, 10:52 AM
Haven't read all the posts, but some referred to MPG. Just a note - I'm running 44's on a 2270 and even with hard driving, I'm getting 20mpg on the average. Got 25+ on a 2500 mile road trip. High teens with a heavy foot. 
Posted by: Gatornapper Oct 18 2017, 06:56 PM
As you are running a 2270, I know it wouldn't apply - but still would be interested in knowing the sizes of your venturi's, main jet and air jet........
thanks,
GN
Haven't read all the posts, but some referred to MPG. Just a note - I'm running 44's on a 2270 and even with hard driving, I'm getting 20mpg on the average. Got 25+ on a 2500 mile road trip. High teens with a heavy foot.
Posted by: kgruen2 Oct 19 2017, 02:04 AM
As you are running a 2270, I know it wouldn't apply - but still would be interested in knowing the sizes of your venturi's, main jet and air jet........
thanks,
GN
Haven't read all the posts, but some referred to MPG. Just a note - I'm running 44's on a 2270 and even with hard driving, I'm getting 20mpg on the average. Got 25+ on a 2500 mile road trip. High teens with a heavy foot.
Venturi - 36
Main jet - 155
Idle jet - 55
Air correction jet - 200
Emulsion - F11
Hope this is helpful. Karl
Posted by: Gatornapper Oct 19 2017, 06:21 AM
Thanks - wow, large main. Don't know about air correction and emulsion jet.
What in the world is emulsion? Have to read my Weber Tech manual.....
As you are running a 2270, I know it wouldn't apply - but still would be interested in knowing the sizes of your venturi's, main jet and air jet........
thanks,
GN
Haven't read all the posts, but some referred to MPG. Just a note - I'm running 44's on a 2270 and even with hard driving, I'm getting 20mpg on the average. Got 25+ on a 2500 mile road trip. High teens with a heavy foot.
Venturi - 36
Main jet - 155
Idle jet - 55
Air correction jet - 200
Emulsion - F11
Hope this is helpful. Karl
Posted by: Gatornapper May 8 2020, 08:31 AM
Almost 2 1/2 years later........an update........
Engine is running GREAT with lots of mid-range torque with the IDF-44's, but took a long time to get there. Here's what it took:
Venturis: 36mm
Main jets: 135
Idle jets: 60
A/C jets: 175
Emulsion: F11
Pump jets: 50
Pump jet valve: 50 w/no bypass
AND an 050 distributor.
All jets are as Porsche dealer had them, when I got the car, except for idle jets which were 50's, and pump jet valve which had bypass. I could not get a good idle with the 50's.
I tried 32mm venturi's - engine had half the power of the original 36's at all RPM - car would not get out of its own way......was a dog. Totally unacceptable. Don't know why since so many say the 44's need the 32mm venturis - I just could not get them to work. Clearly they are better carb tuners than I am.
My car runs far stronger than I ever dreamed a little 2.0 could. My good friend Rickb45 has a new 2.0 with a cam for carbs and Dellorto 40's - and I've driven it......sure seems to me my car is faster at WOT than his, and my mid-range is fine - as he will attest - as he has driven mine several times. Really want to drag-race the cars to find out - but, as that's illegal, we'll have to find another way. Like time 0 - 60 runs with stopwatch.
So no thoughts of putting the D-jet in - I still can't see how it could provide the power I have now, in spite of the limitations of the cam, etc. I'll keep the D-jet I got from Ken Steele so when I'm gone my family can get more $$ for the car if they decide to sell it.
Me? I'm keeping the car, no plans to ever sell it. Had no idea a well-running 914 was so much fun to drive and would have half the power this little 2.0 has. It will be my go-to car....just hate to be putting all the miles on it....just turned 63k - 2400 miles my doing.....in last year.
Will be moving on to improving suspension in the next year.......as well as a repaint to the original Malaga Red.
Thanks to all here for all the input....
GN
have at it bro. but a statement like you want more power than d-jet is capable of is moronic. you can get more power, less longeivty out of a 2.0l type 4, but d-jet is not the limiting factor. displacement, compression ratios, flow, etc, are. d-jet works for up to 2500cc without cam or ecu mods. so, flow your head, deck your cylinders, do cams, and run 44's. oh, wait, then its not a stock 2.0l type 4, then,is it. no, now you are in raby territory. great engines with the r&d to back up, but at $20k you get what you pay for. whoever told you 44's are a better delivery fuel system is an idiot, ever though they dont work on allot of 914's.
Posted by: dr914@autoatlanta.com May 8 2020, 09:02 AM
44s for racing only
Questions re: Weber 44 IDF carbs:
1. Is anyone running these on a stock engine, and if so, how do they perform? National Carburetors kit for stock engines is 34 ICT's, lightly modified 40 IDF's, and only 44's on heavily modified engines.
2. What problems do you introduce using 44's? other than dumping too much fuel in the engine......
3. Venturi's are 45mm, someone pointed out that one should use 40mm venturi's - is that with a stock engine?
4. Anyone run 44's and then convert back to EFI? How did that go? Labor cost?
TIA,
GN
Posted by: Gatornapper May 8 2020, 01:40 PM
And that explains it. P.O. raced 911's, bought this for his university professor girlfriend, and thought she'd want to drive it like he would I assume and set it up accordingly.
And yes, I often have a heavy foot. But as I'm getting 25 - 30mpg, not that often. The engine is very happy at 2500 RPM and up.....and very smooth below.....
And I could not be more pleased with how the engine is running and am very happy with it. And other 914'ers who know about it agree.
As always George, thanks for the feedback.
And huge thanks for free testing of my VR's, I owe you postage back - and will be placing an order soon.........
GN
[quote name='dr914@autoatlanta.com' date='May 8 2020, 09:02 AM' post='2812986']
44s for racing only
Posted by: Gatornapper May 9 2020, 10:08 AM
Just chatted with the PO......it was no less than Peter Gregg who told him to put the 44's on the stock 2.0.
And yes, the local dealer told him they were too big w/o putting in a cam for carbs.....but he went with Peter Gregg's advice.
So the PO knew Peter Gregg before his death in 1980, obviously. Trying to get more info on that. And while Gregg raced 911's and 914-6's, he surely knew the 2.0's quite well too.
And yes, this matches with what you said George........
GN
Posted by: mepstein May 9 2020, 10:11 AM
Jake had told me to use 44's if I built up a high performance 2270. He said the 40's I had could be modified but the 44's would be best for a 175+ hp type 4.
Posted by: Bleyseng May 9 2020, 10:40 AM
All this badmouthing Djet, bah. Its a simple system, runs better than carbs as that's why Porsche used it.
Problems are the FI wiring harness which lays on the hot engine and gets brittle with little shorts in it. Get a new harness.
Problem #2 is the MPS blows out making the car run rich, really rich. New diaphragms are available now and the MPS is easily calibrated to stock.
Problem #3 is the CHT goes out and the engine runs super rich. This is the ONLY failure I have had with Djet since 1998 and it happened in my driveway.
I had 40 Dells on my car when I bought it and 1995 and had soo many problems with them. Keeping them in sync, cold starting was a hassle, etc. Run great at full throttle but who drives around at full throttle?
The stock Djet 2.0L throttle body is 45mm.
Posted by: mepstein May 9 2020, 10:43 AM
All this badmouthing Djet, bah. Its a simple system, runs better than carbs as that's why Porsche used it.
Problems are the FI wiring harness which lays on the hot engine and gets brittle with little shorts in it. Get a new harness.
Problem #2 is the MPS blows out making the car run rich, really rich. New diaphragms are available now and the MPS is easily calibrated to stock.
Problem #3 is the CHT goes out and the engine runs super rich. This is the ONLY failure I have had with Djet since 1998 and it happened in my driveway.
I had 40 Dells on my car when I bought it and 1995 and had soo many problems with them. Keeping them in sync, cold starting was a hassle, etc. Run great at full throttle but who drives around at full throttle?
The stock Djet 2.0L throttle body is 45mm.
A stock FI engine is a pleasure to drive.
Posted by: Gatornapper May 9 2020, 07:52 PM
I have never badmouthed D-jet, and up until recently when I finally got the 44's dialed in, considered it an option once the solid internals of the engine itself was established.
I am good with carbs, and have been doing them for over 50 years, although Weber's are new to me - now I really like them.
Totally understanding the limitations of a cam for FI without the lift or duration needed for carbs, I still can't understand how the air from 4-36mm venturi's can be matched by the air through one 45mm throttle body......but my old memory thought I measured my '76 D-jet system as having a 34mm throttle body.....all packed away nicely now, but I may just unpack it to re-measure it again. I may be wrong. Won't be 1st time, won't be last.
And no question FI is better than carbs overall....hands down. First worked on them in 75 on a '72 Volvo.....loved the system.
One other question: have I heard incorrectly that the ECU's often go bad, and good rebuilt ones are very hard to find? I think even Eric at PMB told me that, and strongly advised me to not put the D-jet in the car.
GN
All this badmouthing Djet, bah. Its a simple system, runs better than carbs as that's why Porsche used it.
Problems are the FI wiring harness which lays on the hot engine and gets brittle with little shorts in it. Get a new harness.
Problem #2 is the MPS blows out making the car run rich, really rich. New diaphragms are available now and the MPS is easily calibrated to stock.
Problem #3 is the CHT goes out and the engine runs super rich. This is the ONLY failure I have had with Djet since 1998 and it happened in my driveway.
I had 40 Dells on my car when I bought it and 1995 and had soo many problems with them. Keeping them in sync, cold starting was a hassle, etc. Run great at full throttle but who drives around at full throttle?
The stock Djet 2.0L throttle body is 45mm.
Posted by: thelogo May 9 2020, 10:47 PM
Use some common sense
Is your car a daily driver. D in djet stand for daily .
Its the best at that.
Or
Is your car a once a week to a car show driver .
Webbers will be more fun if your driving more
Aggressively/ flat out
Posted by: Bleyseng May 9 2020, 11:27 PM
ECU's went bad after battery acid dripped all over them over the years or people tossed them in a box out in the yard so rain rusted them out. They are state of the art 1960's electronic aircraft quality.
I have three of them collected over the years- 73 2.0, 74 2.0L and 75-76 2.0L and they all work fine. Sold the others I had to people needing one.
Posted by: Gatornapper May 10 2020, 07:27 AM
Car is daily driver, not a show car & never will be, but the Weber's are on and working well for my daily driving....and I will admit, I am somewhat heavy-footed in the 914 sometimes - but more than half the time happy with slow easy acceleration - thus my 25 - 30 mpg......
One other thing is - I live in the country, and do little city driving in the 914....and most of the roads around me and to the west are twisty - and I love pushing the car through the turns.......not the usual driving of most folks.......
For me to put my D-jet on would a.) a lot of work; b.) a lot of trouble-shooting as PO of the D-jet said engine was not running well when he pulled it from his '76 and that's why he pulled it; c.) I'm an electrical guy with FI experience so from all the stuff on the web (like rennlist, bowlsby.com, etc.) I think I can probably trouble-shoot it, but my concern is what if the ECU is bad?
Everyone has me so sold on the advantages of the D-jet, I'm willing to try it after doing a lot of other things I want to do on the car - but many have said, "Don't mess with it if the carbs are running well." They are.
Maybe in a year or 2 when other priorities die down, Lord-willing, I'll try the D-jet just to see what it's like......I'm 75 and with this virus every day is a gift, and no tomorrow is guaranteed.......but in one sense, I'd kind of like the challenge of getting the D-jet on and running well.
Then I could decide which I like best....
GN
PS: The ECU I have clearly says it is re-built.......but no one is doing that anymore, right?
Use some common sense
Is your car a daily driver. D in djet stand for daily .
Its the best at that.
Or
Is your car a once a week to a car show driver .
Webbers will be more fun if your driving more
Aggressively/ flat out
Posted by: Gatornapper May 10 2020, 07:35 AM
Question: is there a place where I can have the ECU tested?
GN
Posted by: Bleyseng May 10 2020, 09:22 AM
So it's a 75-76 2.0L ECU? A 052?
I'd have a 914 buddy with a 75-76 2.0L install it in their car to test it. If its bad the car will run like crap or not at all but really if its a rebuilt unit it should be good. If IIIRC correctly the rebuild process just ran a series of tests and maybe resoldered some bad connections. If the ECU isn't hung like stock they can bang around and a solder joint could go bad. That's why they were hung off the battery tray so they avoided banging around.
Posted by: Gatornapper May 10 2020, 02:12 PM
Geoff -
I kind of thought of doing that, but don't know any of the local guys with D-jet very well, not well enough to ask that of them. Don't see any way a bad ECU could hurt their system.
All my local 914 friends are running carbs - or V8's!
So I'll start talking to area 914 owners - I have a great list - and see if any are willing.
Knowing the ECU is good would be strong motivation for me to try the D-jet - testing the other components isn't that hard, and I'd send the injectors to Dr. Injector, and get a new harness from Jeff for sure.
AH! What about the distributor! I'd need a dizzy with the connector for the D-jet too - how hard are they to locate? and what is the Bosche number for them?
Thanks,
GN
So it's a 75-76 2.0L ECU? A 052?
I'd have a 914 buddy with a 75-76 2.0L install it in their car to test it. If its bad the car will run like crap or not at all but really if its a rebuilt unit it should be good. If IIIRC correctly the rebuild process just ran a series of tests and maybe resoldered some bad connections. If the ECU isn't hung like stock they can bang around and a solder joint could go bad. That's why they were hung off the battery tray so they avoided banging around.
Posted by: Gatornapper May 11 2020, 06:31 AM
As I said, PO knew Peter Gregg - pretty well in fact. PO raced both 914's and 911's, and his first instructor was Peter Gregg, who, as all know, did the same and was one of the best. PO met with Greg fairly frequently over 4 or 5 years.
Peter Gregg told him to run 44's on a stock 914 that was a street car and this was the PO's 2nd one with them that he did not race, but used as street car.
GN
Just chatted with the PO......it was no less than Peter Gregg who told him to put the 44's on the stock 2.0.
And yes, the local dealer told him they were too big w/o putting in a cam for carbs.....but he went with Peter Gregg's advice.
So the PO knew Peter Gregg before his death in 1980, obviously. Trying to get more info on that. And while Gregg raced 911's and 914-6's, he surely knew the 2.0's quite well too.
And yes, this matches with what you said George........
GN
Posted by: Bleyseng May 11 2020, 06:39 AM
Geoff -
I kind of thought of doing that, but don't know any of the local guys with D-jet very well, not well enough to ask that of them. Don't see any way a bad ECU could hurt their system.
All my local 914 friends are running carbs - or V8's!
So I'll start talking to area 914 owners - I have a great list - and see if any are willing.
Knowing the ECU is good would be strong motivation for me to try the D-jet - testing the other components isn't that hard, and I'd send the injectors to Dr. Injector, and get a new harness from Jeff for sure.
AH! What about the distributor! I'd need a dizzy with the connector for the D-jet too - how hard are they to locate? and what is the Bosche number for them?
Thanks,
GN
So it's a 75-76 2.0L ECU? A 052?
I'd have a 914 buddy with a 75-76 2.0L install it in their car to test it. If its bad the car will run like crap or not at all but really if its a rebuilt unit it should be good. If IIIRC correctly the rebuild process just ran a series of tests and maybe resoldered some bad connections. If the ECU isn't hung like stock they can bang around and a solder joint could go bad. That's why they were hung off the battery tray so they avoided banging around.
For a dizzy get a 123 one and forget trying to locate a good used one
Posted by: Gatornapper May 11 2020, 07:29 AM
Geoff -
I thought there was a special set of contacts for the D-jet dizzy?????? That connected to the ECU.......
If a 123 dizzy would work, why wouldn't my present nice 050 work?
TIA,
GN
Geoff -
I kind of thought of doing that, but don't know any of the local guys with D-jet very well, not well enough to ask that of them. Don't see any way a bad ECU could hurt their system.
All my local 914 friends are running carbs - or V8's!
So I'll start talking to area 914 owners - I have a great list - and see if any are willing.
Knowing the ECU is good would be strong motivation for me to try the D-jet - testing the other components isn't that hard, and I'd send the injectors to Dr. Injector, and get a new harness from Jeff for sure.
AH! What about the distributor! I'd need a dizzy with the connector for the D-jet too - how hard are they to locate? and what is the Bosche number for them?
Thanks,
GN
So it's a 75-76 2.0L ECU? A 052?
I'd have a 914 buddy with a 75-76 2.0L install it in their car to test it. If its bad the car will run like crap or not at all but really if its a rebuilt unit it should be good. If IIIRC correctly the rebuild process just ran a series of tests and maybe resoldered some bad connections. If the ECU isn't hung like stock they can bang around and a solder joint could go bad. That's why they were hung off the battery tray so they avoided banging around.
For a dizzy get a 123 one and forget trying to locate a good used one
Posted by: 930cabman Apr 26 2021, 05:04 PM
@GN, I am considering using Webers on a stock 2.0 liter/4. It sounds as though the 44 IDF's with 36mm venturis are working well with your ride. Are you still considering changing to a Bosch D jet, or is that history?
Thanks
Posted by: Gatornapper Apr 26 2021, 07:28 PM
Cabman -
Well, I'm keeping the Webers for now, and yes, they are running wonderfully - engine is out of car for last 6 months, and I hope to have it in by end of May. And while many say it's not possible, there are others who confirm that it is.
Many say the 2.0 cannot run well on 44's with 36mm venturi's, but I know it first hand. Great idle, smooth transition to power, and downright bad in WOT.
BUT, that being said, I have an original '76 2.0 D-Jet and I have to find out for myself which I prefer. The ECU and TPS are rebuilt and working like new, all other components just need to be cleaned up, have the injectors tested, get new hoses and a vacuum dizzy and I'm good to go.
I think I could install the D-Jet in a day - but I know it might be quite a while getting it dialed in.
Then I'll make a decision on which I prefer for my driving.
I don't see that happening for at least a year - I've got tons of things to do on the car first. And I can be getting the D-Jet ready in the meantime.
You can be sure I'll post all I learn here.
While saying this, if I were starting from scratch, I'd put 40's on the engine instead of 44's. Too many say 40's are ideal for the engine. If you haven't bought the carbs yet.
And if you don't have them yet, talk to Eric at PMB - he can supply them and you'd get his great support. He's a strong believe in Webers for the 914.
GN
@GN, I am considering using Webers on a stock 2.0 liter/4. It sounds as though the 44 IDF's with 36mm venturis are working well with your ride. Are you still considering changing to a Bosch D jet, or is that history?
Thanks
Posted by: 930cabman Apr 27 2021, 08:19 AM
Cabman -
Well, I'm keeping the Webers for now, and yes, they are running wonderfully - engine is out of car for last 6 months, and I hope to have it in by end of May. And while many say it's not possible, there are others who confirm that it is.
Many say the 2.0 cannot run well on 44's with 36mm venturi's, but I know it first hand. Great idle, smooth transition to power, and downright bad in WOT.
BUT, that being said, I have an original '76 2.0 D-Jet and I have to find out for myself which I prefer. The ECU and TPS are rebuilt and working like new, all other components just need to be cleaned up, have the injectors tested, get new hoses and a vacuum dizzy and I'm good to go.
I think I could install the D-Jet in a day - but I know it might be quite a while getting it dialed in.
Then I'll make a decision on which I prefer for my driving.
I don't see that happening for at least a year - I've got tons of things to do on the car first. And I can be getting the D-Jet ready in the meantime.
You can be sure I'll post all I learn here.
While saying this, if I were starting from scratch, I'd put 40's on the engine instead of 44's. Too many say 40's are ideal for the engine. If you haven't bought the carbs yet.
And if you don't have them yet, talk to Eric at PMB - he can supply them and you'd get his great support. He's a strong believe in Webers for the 914.
GN
Thanks Napper, I have not done business with PMB, but have heard there name quite a bit here. I am new to the 914 arena, but been wrenching for a half a century. I bet either D jet or L jet is more efficient (we have possession of both systems in boxes), but with 50 year old sensors it does not seem the quick/easy/American way
thanks again
@GN, I am considering using Webers on a stock 2.0 liter/4. It sounds as though the 44 IDF's with 36mm venturis are working well with your ride. Are you still considering changing to a Bosch D jet, or is that history?
Thanks
Posted by: MM1 Apr 27 2021, 12:35 PM
Perhaps I missed it - but is your engine a stock 2.0L - with a stock cam?
Posted by: 930cabman Apr 27 2021, 02:35 PM
Perhaps I missed it - but is your engine a stock 2.0L - with a stock cam?
Unknown, the GC engine came to me as part of a package deal. Seller told me the engine "needs rebuild". I pulled the valve covers, very clean, ran a compression check, 120 - 125 - 120 - 130 (quite happy with those, cold engine) and checked oil pressure while cranking: 15lbs. From what I can tell this might be a good engine. While removing some of the D jet stuff I found several potential running issues.
My gut tells me YES, stock GC engine
Posted by: Gatornapper Jul 14 2021, 04:29 PM
Just an update on my last post after another "dialing in" of my Weber 44's:
Did another fine-tuning of the carbs last Saturday and just want to report my engine - on Weber 44's - could not be running better. I definitely saw some improvement Saturday.
I can say under all load conditions, all RPM, and all combinations of the two the engine runs like a dream. Picks up load smoothly and easily from all states and I see no weak spots.
WOT of course is far beyond my expectations, and I am content with the power of the engine as it is - with a stock original cam.
Cruising at 35, 45, 55 or 75, the car is a dream. Applying any amount of power in any condition is flawless. The engine is silky smooth pulling on all 4 at all times.
Yes - the plan is still the same. I'm driving the car with the Weber's for a year. Then I'm putting in the D-Jet.
DrPhil has kindly checked out my ECU, MPS (rebuilt with Tangerine parts) and my TPS on his car and they work great, so all I need is to get my injectors tested, buy new electrical harness, plumbing and a vacuum dizzy and install and tune.
That will be next spring or summer.
Meanwhile, I could not be having more 914 fun, sometimes taking the it for 3 hour drives in the mountain foothills of Virginia just for the joy of it. 
Yes - my 914 is more PURE FUN to drive than my '11 Cayman S. Just me, the machine, and the road. If I had to sell one - I'd be tempted to sell the Cayman that is mint.
Hope I don't have to make that decision.
Hoping to find my original post on the car long ago so I can proved updates on the 100+ things I've done to the car in the last year and several hundred hours of work.
GN
Cabman -
Well, I'm keeping the Webers for now, and yes, they are running wonderfully - engine is out of car for last 6 months, and I hope to have it in by end of May. And while many say it's not possible, there are others who confirm that it is.
Many say the 2.0 cannot run well on 44's with 36mm venturi's, but I know it first hand. Great idle, smooth transition to power, and downright bad in WOT.
BUT, that being said, I have an original '76 2.0 D-Jet and I have to find out for myself which I prefer. The ECU and TPS are rebuilt and working like new, all other components just need to be cleaned up, have the injectors tested, get new hoses and a vacuum dizzy and I'm good to go.
I think I could install the D-Jet in a day - but I know it might be quite a while getting it dialed in.
Then I'll make a decision on which I prefer for my driving.
I don't see that happening for at least a year - I've got tons of things to do on the car first. And I can be getting the D-Jet ready in the meantime.
You can be sure I'll post all I learn here.
While saying this, if I were starting from scratch, I'd put 40's on the engine instead of 44's. Too many say 40's are ideal for the engine. If you haven't bought the carbs yet.
And if you don't have them yet, talk to Eric at PMB - he can supply them and you'd get his great support. He's a strong believe in Webers for the 914.
GN
@GN, I am considering using Webers on a stock 2.0 liter/4. It sounds as though the 44 IDF's with 36mm venturis are working well with your ride. Are you still considering changing to a Bosch D jet, or is that history?
Thanks
Posted by: ClayPerrine Jul 15 2021, 11:06 AM
If I may suggest something:
http://www.allzim.com/store/356-efi-conversion-faq.html
This is an EFI conversion kit for the 356 motor. It is a bolt on replacement for the stock carbs. I helped with some of the development of this kit. It will fit on a carbed 914 engine, but you won't be able to use the manifolds that come with it.
The base map in the ECU would work for initial running. But you would have to tune it for your car.
I have driven the first 356 with this kit. It starts great, idles smooth and pulls stronger than the carbed version of the exact same car.
They have 3 running cars with the kit on them.
Contact @http://www.914world.com/bbs2/index.php?showuser=21587 . He is the person developing this kit for Zims.
Clay
Posted by: Gatornapper Jul 15 2021, 07:44 PM
Clay -
Is this for me? Did I miss something? Lost me on 356 engine.
So will this EFI conversion work on my 2.0?
Not sure what you mean by not using the manifolds that come with it......what manifolds would I use? I have original D-Jet manifolds and the manifolds for my 44's.
Yes - I would be very interested. I can always sell a proven working D-Jet system for a 2.0 & use that for the EFI.
Thanks!
Richard
If I may suggest something:
http://www.allzim.com/store/356-efi-conversion-faq.html
This is an EFI conversion kit for the 356 motor. It is a bolt on replacement for the stock carbs. I helped with some of the development of this kit. It will fit on a carbed 914 engine, but you won't be able to use the manifolds that come with it.
The base map in the ECU would work for initial running. But you would have to tune it for your car.
I have driven the first 356 with this kit. It starts great, idles smooth and pulls stronger than the carbed version of the exact same car.
They have 3 running cars with the kit on them.
Contact @http://www.914world.com/bbs2/index.php?showuser=21587 . He is the person developing this kit for Zims.
Clay
Posted by: mepstein Jul 15 2021, 08:21 PM
If I may suggest something:
http://www.allzim.com/store/356-efi-conversion-faq.html
This is an EFI conversion kit for the 356 motor. It is a bolt on replacement for the stock carbs. I helped with some of the development of this kit. It will fit on a carbed 914 engine, but you won't be able to use the manifolds that come with it.
The base map in the ECU would work for initial running. But you would have to tune it for your car.
I have driven the first 356 with this kit. It starts great, idles smooth and pulls stronger than the carbed version of the exact same car.
They have 3 running cars with the kit on them.
Contact @http://www.914world.com/bbs2/index.php?showuser=21587 . He is the person developing this kit for Zims.
Clay
What do you think about using it on a 67, 912
Posted by: rhodyguy Jul 16 2021, 09:33 AM
That Allzim package is $3.5k 
For a 2056 the 44s with a 32mm Venturi swap are the ticket. Cleaner transition. The 28s run out of steam.
Posted by: Gatornapper Jul 16 2021, 09:42 AM
R -
I'm running 36mm venturi's with best performance by far and no issues.
2 years ago trying to get the 44's dialed in, I tried 32mm venturis as they were the recommended solution by a top 914 mechanic.
I could not get them to work. Engine ran fine, but had zero power - no torque at all at any rpm or under any load.
I went back to the 36's that were originally in the carbs when installed by the local Porsche dealer many years ago.
Had idle problems that were solved by going from .050 to .060 idle jets. Dialed in carbs and they work great, all conditions, tho many say that's impossible.
Torque above 50% throttle is great, below that is fine - very smooth acceleration, no stumbling.
GN
That Allzim package is $3.5k
For a 2056 the 44s with a 32mm Venturi swap are the ticket. Cleaner transition. The 28s run out of steam.Posted by: Gatornapper Jul 16 2021, 10:08 AM
Cabman -
I'm sure the D-Jet is more efficient too, but I'm getting 27mpg with my 44's on regular driving, so I don't see efficiency as an issue.
I can't see the D-Jet getting anywhere near the WOT power of Webers, if because of nothing other than the size of the throttle body. Yes - I know the camshaft is a major limiting factor as well, but it just makes sense more oxygen can get through WOT carbs than the D-Jet throttle body - and oxygen is 10x more of an influence on the power of fuel ignition than fuel quantity.
Because the 2.0 is such a low-power engine, I use over 50% throttle a lot.
Next year I'll put in my D-Jet and know first hand which I like better.
Oh - the old FI systems are really simple. I worked on Bosch FI similar to D-Jet in the late 70's on Volvo's and found them fairly easy to diagnose and work on. There's a site with how to test every component in the D-Jet.....have it somewhere, & it's linked here on 914world.
GN
Cabman -
Well, I'm keeping the Webers for now, and yes, they are running wonderfully - engine is out of car for last 6 months, and I hope to have it in by end of May. And while many say it's not possible, there are others who confirm that it is.
Many say the 2.0 cannot run well on 44's with 36mm venturi's, but I know it first hand. Great idle, smooth transition to power, and downright bad in WOT.
BUT, that being said, I have an original '76 2.0 D-Jet and I have to find out for myself which I prefer. The ECU and TPS are rebuilt and working like new, all other components just need to be cleaned up, have the injectors tested, get new hoses and a vacuum dizzy and I'm good to go.
I think I could install the D-Jet in a day - but I know it might be quite a while getting it dialed in.
Then I'll make a decision on which I prefer for my driving.
I don't see that happening for at least a year - I've got tons of things to do on the car first. And I can be getting the D-Jet ready in the meantime.
You can be sure I'll post all I learn here.
While saying this, if I were starting from scratch, I'd put 40's on the engine instead of 44's. Too many say 40's are ideal for the engine. If you haven't bought the carbs yet.
And if you don't have them yet, talk to Eric at PMB - he can supply them and you'd get his great support. He's a strong believe in Webers for the 914.
GN
Thanks Napper, I have not done business with PMB, but have heard there name quite a bit here. I am new to the 914 arena, but been wrenching for a half a century. I bet either D jet or L jet is more efficient (we have possession of both systems in boxes), but with 50 year old sensors it does not seem the quick/easy/American way
thanks again
@GN, I am considering using Webers on a stock 2.0 liter/4. It sounds as though the 44 IDF's with 36mm venturis are working well with your ride. Are you still considering changing to a Bosch D jet, or is that history?
Thanks
Posted by: NARP74 Jul 16 2021, 10:21 AM
Following along and learning. On a related note, this guy is converting his FI to Haltech EFI on his 914. He has a complete list of parts and cost, and has put up videos on the whole process to watch.
https://www.youtube.com/channel/UCQ-xGi9PJL97VHOH77sOD4Q/videos
Might not be on here, in one episode he says no one his age uses 914World. They are probably just on social media...
Posted by: 914_teener Jul 16 2021, 10:45 AM
I have never badmouthed D-jet, and up until recently when I finally got the 44's dialed in, considered it an option once the solid internals of the engine itself was established.
I am good with carbs, and have been doing them for over 50 years, although Weber's are new to me - now I really like them.
Totally understanding the limitations of a cam for FI without the lift or duration needed for carbs, I still can't understand how the air from 4-36mm venturi's can be matched by the air through one 45mm throttle body......but my old memory thought I measured my '76 D-jet system as having a 34mm throttle body.....all packed away nicely now, but I may just unpack it to re-measure it again. I may be wrong. Won't be 1st time, won't be last.
And no question FI is better than carbs overall....hands down. First worked on them in 75 on a '72 Volvo.....loved the system.
One other question: have I heard incorrectly that the ECU's often go bad, and good rebuilt ones are very hard to find? I think even Eric at PMB told me that, and strongly advised me to not put the D-jet in the car.
GN
All this badmouthing Djet, bah. Its a simple system, runs better than carbs as that's why Porsche used it.
Problems are the FI wiring harness which lays on the hot engine and gets brittle with little shorts in it. Get a new harness.
Problem #2 is the MPS blows out making the car run rich, really rich. New diaphragms are available now and the MPS is easily calibrated to stock.
Problem #3 is the CHT goes out and the engine runs super rich. This is the ONLY failure I have had with Djet since 1998 and it happened in my driveway.
I had 40 Dells on my car when I bought it and 1995 and had soo many problems with them. Keeping them in sync, cold starting was a hassle, etc. Run great at full throttle but who drives around at full throttle?
The stock Djet 2.0L throttle body is 45mm.
Do what you know:
But know this...just because a carb has a certain size opening does not mean the engine will make more power. Power is express by the VE curve which is short for volumetric efficency. The reason the automotive industry went to FI was because it is simpler and more efficient to make power.
I think any FI system is easy to understand...they all work pretty much the same way. Porsche along with Bosch did some amazing things with it going back all the way to the Messcherschmidt in aeronautics in WW2 as you may know.
You may have heard wrong. The ECU in the 914 is very robust and hardly ever burns out. They can be tested and fixed there are a few companies that do this.
A Good read on induction with carburators. https://mooregoodink.com/induction-science/
This is no simpler to do that setting up an FI system. Really it's just a matter of money. Eric does good work and is a good business person.
With regard to your 050 dizzy. There are better electronic replacements I think and if you like and spending time on those types of things then...that's okay do that.
I'd rather drive the car then tinker and wonder why it's "better". But that's me.
Good luck on your journey.
Posted by: Gatornapper Jul 17 2021, 06:31 AM
914 Teener-
Of course you are accurate on your first paragraph.
As to my D-Jet:
DrPhil has been incredibly kind in testing my ECU, MPS and TPS in his car. ECU is fine, TPS needed cleaning, is fine. MPS needed a Tangerine rebuild kit which he graciously put in. All I need now is to have injectors tested, get new wiring harness and plumbing.
As to my carbs:
I studied Bob Tomlinson's "Weber Tech Manual" - Super Tune-Up Guide for VW and Porsche Engines. That and the grace of God are what helped me get my 44's dialed in.
There is a Table "Weber Jetting Guide for Air-Cooled VW Engines on P. 64. Jetting for Dual IDF 44's in a 2000cc engine says:
Venturi: 36mm - Mine: 36mm
Main: 155 - 180 - Mine: 135
A/C: 2.00 - Mine: 2.00
E/Tube: F11 - Mine: F11
Idle: .60 - Mine: .60 (Car came to me with .50's, but I could not get a good idle with them.
P/Jet: .50 - Mine: .50
Another item helped carb performance: Pump bypass valve normally has 50% return to float bowl. Mine have 0% return, with 100% of fuel going into the throats. A Weber expert recommended this.
Took my car yesterday to a member in Virginia who is a top expert in VW engines having built and raced them for years, who also has a 914. He drove it. He said my idle is as good as it gets, and gave my carb performance an A. Made my day.
As every 914 owner who has driven my car has said, it is amazingly tight. I am grateful.
As to my 050 Dizzy - amazing improvement in engine power and performance from 009 that was in car when I got it. Night and day. Be nice some day to get a 123, but they are expensive. I am running Pertronix ignition in the 050.
Hope this may be of help with anyone else running Dual IDF-44's on a 2.0 engine.
GN
Do what you know:
But know this...just because a carb has a certain size opening does not mean the engine will make more power. Power is express by the VE curve which is short for volumetric efficency. The reason the automotive industry went to FI was because it is simpler and more efficient to make power.
I think any FI system is easy to understand...they all work pretty much the same way. Porsche along with Bosch did some amazing things with it going back all the way to the Messcherschmidt in aeronautics in WW2 as you may know.
You may have heard wrong. The ECU in the 914 is very robust and hardly ever burns out. They can be tested and fixed there are a few companies that do this.
A Good read on induction with carburators. https://mooregoodink.com/induction-science/
This is no simpler to do that setting up an FI system. Really it's just a matter of money. Eric does good work and is a good business person.
With regard to your 050 dizzy. There are better electronic replacements I think and if you like and spending time on those types of things then...that's okay do that.
I'd rather drive the car then tinker and wonder why it's "better". But that's me.
Good luck on your journey.
Posted by: ClayPerrine Jul 17 2021, 06:53 AM
Clay -
Is this for me? Did I miss something? Lost me on 356 engine.
So will this EFI conversion work on my 2.0?
Not sure what you mean by not using the manifolds that come with it......what manifolds would I use? I have original D-Jet manifolds and the manifolds for my 44's.
Yes - I would be very interested. I can always sell a proven working D-Jet system for a 2.0 & use that for the EFI.
Thanks!
Richard
If I may suggest something:
http://www.allzim.com/store/356-efi-conversion-faq.html
This is an EFI conversion kit for the 356 motor. It is a bolt on replacement for the stock carbs. I helped with some of the development of this kit. It will fit on a carbed 914 engine, but you won't be able to use the manifolds that come with it.
The base map in the ECU would work for initial running. But you would have to tune it for your car.
I have driven the first 356 with this kit. It starts great, idles smooth and pulls stronger than the carbed version of the exact same car.
They have 3 running cars with the kit on them.
Contact @http://www.914world.com/bbs2/index.php?showuser=21587 . He is the person developing this kit for Zims.
Clay
The EFI conversion would work on your 914. But you have to use your weber manifolds and throttle linkage with it. The manifolds that come with it are for the 356 engine.
The rest will bolt on.
Clay
Posted by: Gatornapper Jul 17 2021, 07:36 AM
REALLY?
Wow - worth investigating for sure.
BUT I already have a nice D-Jet close to ready for installation.
What would this EFI system get me other than a modern system for several thousand dollars.......?
Same or better performance?
Thanks Clay.
GN
The EFI conversion would work on your 914. But you have to use your weber manifolds and throttle linkage with it. The manifolds that come with it are for the 356 engine.
The rest will bolt on.
Clay
Posted by: larryM Jul 26 2021, 03:48 PM
as DD said above - What CAM IS IN IT??
D-jet cam with carbs does not fit the Pierce modelling
D-jet with non-stock cam is a LOT of trouble (BTDT)
? you want more D-jet power - bore out the throttle body - it makes a huge mid-range difference - guy name Ed Mazula in SoCal used to do that for us
http://www.914world.com/bbs2/index.php?s=&showtopic=307202&view=findpost&p=2582580
Posted by: 930cabman Jul 26 2021, 04:48 PM
Have you considered another 914 project? It sounds as though your current ride is smooth, economical and powerful, why change a thing? maybe leave well enough alone?
Posted by: Gatornapper Jul 26 2021, 07:36 PM
Well, still TONS of stuff to do to my 914. See details here:
http://www.914world.com/bbs2/index.php?showtopic=316768&st=160
Don't expect to be finished for a couple years. Meanwhile I'm enjoying driving it! Over 2,000 miles in last month!
GN
Have you considered another 914 project? It sounds as though your current ride is smooth, economical and powerful, why change a thing? maybe leave well enough alone?
Posted by: 930cabman Jul 28 2021, 04:54 AM
It seems as though the consensus here is to go with factory FI in general. I am in the opposite camp. With 50 years old wiring, sensors, ECU, .... the potential for failure is high. Sure, when this is new the factory FI setup is far superior, but they are not new. Several years ago I switched my Alfa spider from L jet to Webers and never looked back. And yes, carbs are not without fault, but the number of variables and relative ease (for an old guy) to get carbs running is better than factory FI. My .02
Posted by: Gatornapper Jul 28 2021, 09:02 AM
I know a few things re- the stock engine:
The engine will never run better than with a good working original D-Jet.
The engine will never have more power half throttle and up than with IDF-44's.
D-Jet parts are getting harder and harder to find. Contrary to many in the 914 community, Eric at PMB is passionate about NOT going with the D-Jet for that reason, and going with Weber's.
Also, contrary to the belief of many, IDF-44's can be tuned to run great for everyday driving. And I am not the only one who has done this. Yes, IDF-40's are more ideally suited for the 2.0, but I did not inherit them and have no reason to spend the $$$ to go back to them.
GN
It seems as though the consensus here is to go with factory FI in general. I am in the opposite camp. With 50 years old wiring, sensors, ECU, .... the potential for failure is high. Sure, when this is new the factory FI setup is far superior, but they are not new. Several years ago I switched my Alfa spider from L jet to Webers and never looked back. And yes, carbs are not without fault, but the number of variables and relative ease (for an old guy) to get carbs running is better than factory FI. My .02
Posted by: Gatornapper Jul 28 2021, 09:05 AM
IF I did have another project, it would be to find, rebuild and install a nice 3.0 or 3.2 911 engine.......in my present 914......but that is more than I can handle technically......
Have you considered another 914 project? It sounds as though your current ride is smooth, economical and powerful, why change a thing? maybe leave well enough alone?
Posted by: rfinegan Jul 28 2021, 10:11 AM
I started with 44 idf and went to 40 IDF on my 2.0 . Now I am going back and buying another set of 44 IDF for my 2056 build. The Mid to Top power with headers is amazing
Posted by: 930cabman Jul 28 2021, 06:23 PM
I started with 44 idf and went to 40 IDF on my 2.0 . Now I am going back and buying another set of 44 IDF for my 2056 build. The Mid to Top power with headers is amazing
I was following you build somewhat ( last I saw you were getting the rocker geometry proper) it's alive!! great news. I am about to assemble the case/crank soon. My local NAPA is doing a standard valve job on my heads and Dema (Elgin cams) is grinding my core for a minor upgrade. Weber 40 IDF will top things off.
Posted by: Gatornapper Jul 30 2021, 07:08 AM
If anything on my engine craps out, I'm headed the same way on the 2056 build and headers.......you can be my guide........
GN
I started with 44 idf and went to 40 IDF on my 2.0 . Now I am going back and buying another set of 44 IDF for my 2056 build. The Mid to Top power with headers is amazing
Posted by: rfinegan Jul 30 2021, 08:05 AM
I was a master mechanic in my youth, now I'm a Quality Assurance Software Engineer.
It is all about a documenting a repeatable path.
I sure hope this is a GOOD / Happy Path to repeat and not a BUG/Failure!
Im always available for insight either way
-Robert
If anything on my engine craps out, I'm headed the same way on the 2056 build and headers.......you can be my guide........
GN
I started with 44 idf and went to 40 IDF on my 2.0 . Now I am going back and buying another set of 44 IDF for my 2056 build. The Mid to Top power with headers is amazing
Posted by: 930cabman Jul 30 2021, 09:02 AM
I learned early "repeatability" is the key, without this, we are wandering
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