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.

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

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

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.

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?

Question: is there a place where I can have the ECU tested?

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.

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

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

For a dizzy get a 123 one and forget trying to locate a good used one

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

@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

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

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

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

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 @partsguy22 . He is the person developing this kit for Zims.

Clay

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

What do you think about using it on a 67, 912

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.

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

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

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-xGi9PJL...H77sOD4Q/videos

Might not be on here, in one episode he says no one his age uses 914World. They are probably just on social media...

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.

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

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

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

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=&...t&p=2582580

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?

Well, still TONS of stuff to do to my 914. See details here:

http://www.914world.com/bbs2/index.php?sho...6768&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

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

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

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......

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.

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 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

I learned early "repeatability" is the key, without this, we are wandering