My 914 has been sidelined since 2012 for a number of reasons but was parked not running. Pulled it out of mothballs and hauled it over to the local vintage Porsche mechanic who said my impulse sender had no signal. He said he was unable to source parts for it and was unsure if replacing that part would get it back on the road his recommendation was to convert to Weber 40's. I'm not rich so I understand his hesitancy to open what could be a very expensive can of worms.

So here is where my questions start

I'm just looking for a solid running reliable car that I can drive on trips and maybe autocross 2-3x per year.

anyone have a source on the impulse senders? can they be rebuilt?

Is the Carb it advice good?

I have a basically stock 2.0 with hydraulic lifters and a very mild cam.

Will I have to change my cam to convert it?

what's the best carb? I have seen 34's 40's and 44's people seem to do all three are there pros and cons to each setup?

Can I get this conversion done for around $1500 in parts and is it a achievable project for an average mechanic? I suck with electrical but I have plenty of tools and am not afraid to learn as I go. I have done head gaskets and other mid level projects before.

which motor and injection system are on the car?

you can learn fuel injection
there is a lot of experts around here
I am not familiar with your mechanic's term of "impulse injector"
as there is no part with that name... so the mechanic is talking about something with a different name...

possibly the MPS
manifold Pressure Sensor

but there are other items it could be.
I'd look up brad anders website and read it 3x
then go part by part and test each of your Fuel injection components

some description of how it was "running poorly" when it was parked would help also

If you fix it yourself... your probably talking about a few hundred dollars
you may do other maintenance things like changing out all of the vacuum lines while your there... and that could cost a little extra... but should not run up to the 1500 limit your expecting for the carbs.

The Fuel injection system is not very happy with cam lift.
so depending on which cam you put in... that may matter also

brant

I swapped over to carbs for the same reason; parts were just hard to find and I got tired of trouble shooting the FI system.
Now parts are a LOT more available, and the FI knowledge is more accessible.
However, I still do not have ANY regrets making the swap.
Cleaner engine bay and easier trouble shooting.
You can pull your existing FI and put on a set of carbs with minimal effort.
I went with the EMPI HPMX 40s.
Pretty easy install.

You can carb it!

You will not need to change the cam, you should as the one that is in it is probably setup for FI, but you don't need to. You did say it is a mild one. Which one is in there?

You can do it for under $1500 depending on your mechanics labor rate. The carbs run close to $1000 I believe for a set of 40 Webers. 40 Webers are what you should go with. You will need a different Fuel pump or a really good regulator to drop down the FI pump. The linkage is where you can spend a lot or a little.

Tangerine Sync Link - Set them and forget them $300
CSP - good quality center pull system $150
Hex bar - Cheap garbage. Will work at first then start to deteriorate free when you buy a kit

The $1000 kit should also contain the manifolds. You may need to buy the phelonic? spacers/gaskets between the intakes and the heads.

So you can see you get pretty close to the $1500 mark in just parts. I feel carbs are very reliable and simple.

BUT but BUT but BUT...

FI does work well when it has no vac leaks or wire issues and was meant for that engine. It is reliable once it is all working. You can probably get almost a completely refreshed FI system for $1500 or under. I don't like dabbling in the dark magic as my brain is too simple to work with complex wires and hoses and wires and thingies. From what I have worked with is runs nice. The jury is still out on whether I like djet or ljet more. If you replace the wire harness and the vac lines and test all the components individually, replacing the ones out of spec, you should be pretty close to a reliably running car. Also, learn the items yourself since most mechanics don't know the simplest spell in an ancient old magic.

The part was the impulse sender that he could not find. So far I have not been able to either but said part does seem to exist. I googled it and found it for lots of other cars. for the 914 its NLA. Is there ayone that sells used parts for this?

The blinker fluid is also hard to come by.

Signed:
Resident smart

Time for a new mechanic in my opinion. I've been in the automotive industry for 27 years and have no idea what is meant by an impulse sender in the context of a 914.

It could be interpreted to be any sort of Hall Effect sensor (Crankshaft, camshaft, speedometer, ABS sensor, etc.). Of which, the 914 Fuel Injection system has zero.

Could it mean:
Injector trigger points? Maybe -- but can be obtained with some work.

Ignition points -- These are definitely available so suspect that isn't what he means.

Source for trigger points in a pinch - not completely unavailable.

Click to view attachment

all of the FI parts are out there...
even if it means rebuilding the MPS yourself with a diaphram from CFR

but I still have no idea what an IMPULSE sender is.
that is the wrong word for what ever part he is trying to describe.
maybe call the mechanic and get him to explain what an "impulse sender" does... then we can translate it into the correct term to help

I like superhawks idea... he might mean the trigger points in the distributor

like I said... anything can be found, even if its in the form of a good used one...
but you have to know the correct label for "impulse sender" before you can search one.

if you found something on the internet, maybe send us a picture of it


also... as a warning... there are very few mechanics left that still know this injection system. most of those guys are long gone, and all cars quit using Djet sometime in the late 1970's

so I would be highly suspect of any mechanic's diagnosis
unless they specialized in old volkswagens, most of them have no clue

even if its the "impulse injector" and you buy one... your mechanic could be far off.
I'd test it myself before spending the money. How did he test it? How did he diagnose it? Like I said... most mechanics have no clue when it comes to antique fuel injection
and that is likely the reason that most mechanics just want to sell you a set of carbs...

because 99% of them don't know how to fix it.

brant

On a more pleasant note:

If you are limited on monetary resources, carbs are a very viable option but if you are unable to do the work on them yourself, you will quickly find that they they too can be maintenance intensive over a couple years time which could put you right back at the mercy of a good mechanic as they age and need rebuilds.

Getting harder and harder to find mechanics that are good with carbs .

keep the fuel injection call for advice, do not incur needless expense, do not devalue your car and make it unreliable

please tell us what year and motor you have
there are 2 different (stock) fuel injection systems for a 914

one is called Djet
the other is Ljet

different components and theory
so you have to tell use which system you have



EDIT
I just saw your signature
if its stock components for a 1973 2.0
then you have a Djet system


sorry I didn't see that previously.

The good news: it's probably something really simple to fix.

The bad news: it will take less time to install the carbs than it will take you take you diagnosis the problem with the FI.

You probably don't want carbs then.

Yes they will work, but they will be neither as solid running or as reliable as sorted fuel injection.

While the engineering behind D-jet is pretty complicated the actual troubleshooting and maintenance of it is pretty simple once you familiarize yourself with it. As stated, check out Brand Anders D-jet site. There are really only a couple major components that will cause serious issues and they are fairly simple to bench test.

I'm a newby here and am working on getting the FI system on my '74 2.0 up to snuff. Not that complicated. Anyway, Brad Anders has a discussion about the tradeoffs between the stock D-Jet FI system and carburetors which has some interesting information and perspective:

https://members.rennlist.com/pbanders/carbs.htm

I've owned a car with carbs and a car with stock FI. The FI required less maintenance and tinkering. If you already have the FI, just clean it up and make it work.

What hasn't been brought up (in this thread) that bears repeating ....
FUEL! The fuel mixes today SUCK unless you are fortunate & buying
non-ethanol fuel.
Unless you are driving the car daily these fuels exacerbate the challenges with carbed cars.

All I can say is with my Porsche cars with FI, they start right up. It never mattered if my car sat for 6 months with a battery tender on it started right up. This is with fuel for California. I say FI is best. I am thinking of putting FI on my RAT Eng. that has carbs now

Yes, this engine was in one of Oscars cars



Bob B.
Click to view attachment

Carbs FTW
I do believe an impulse sender is what we call a bar tender up here on Mass.

All joking aside, just fix the FI
It’s most likely something stupid simple.

Looking at your location quickly I found
Modern Aircooled
And
Victory motors
Koby
And a few others

Houston has a decent Porsche car culture so I suggest you might want to look around for a shop that remembers how to work on your era of air cooled classic Porsches and VW because the FI is basically the same.

It can only be the trigger points (although impulse has such a nice star trek ring to it). I would suggest spending 400 on a 123 ignition as the triggers are getting to unobtainium and that will also address the points issues. The rest of the djet is available and reliable and we can help you sort it out.

Just fyi, my 73 2.0 djet was near basket case due to well meaning mechanics. It cost me about 1000 dollars to get it running perfectly. 4 injectors, rebuilt mps, new hoses, cleaning, and some new boots and gaskets, the new 123dizzy, and more gauges than god.

Ditto for me. From my perspective working with 50 years old electronics is just too problematic. I have done the conversion with several cars and never looked back.

Sure, when the Bosch FI system was new, it was unbeatable, but she has her issues when old.

Going carbs? Figure out which distributor you are going to use. Buy a carb balancing tool. Add a fuel pump for carbs that is self regulated, figure out where you intend to mount the pump, buy the CB Weber manual, don't buy a cross bar linkage dependent on springs to keep it centered, replace every piece of fuel line with line for modern fuels, new fuel sock in the tank, phenolic spacers/gaskets under the intakes. Stock up on patience.

Before I add more, let me say I'm in the camp of keeping FI if at all possible.

However, going to carbs is pretty darn simple let's not make it out to be rocket science. I figured it out as a 20 year old bone head. K-mart tools and timing light were about all I had back in those days.

We put so many rules on folks (yes I know I do too . . ). The best 914 is one that is driven!


My 1.7L carb conversion broke all the rules we know all know to be DAPO stuff in hindsight:

Dual 40 IDF's that came with venturi's that were too large and poor out of the box jetting

OEM FI cam

No phonelic manifold spacers. Later just stacked about two or three more gaskets.

I swapped to the 009 centrifugal advance distributor (it was all the rage in the 80's for VW's) with a translucent / clear red distributor cap

Facet 3 psi fuel pump - noisy SOB

Rubber lines in the tunnel (replaced plastic after the metal stubs) since the plastic lines had cracked

Round crossbar / stamped steel linkage (slippage galore ). An aluminum Hex bar would have been a serious upgrade.

Some sort of throttle cable holder made out a piece of 1/8" strap iron that I bent up and attached to the case via case bolt.

Uni-syn carb sync tool (cheapest out there )

And those are just the dumb things I can remember not to mention all the hard lessons I learned along the way about jetting, cam choices, etc.


But you know what . . . . it ran . . . it drove and i fell in love

I have the stock FI, in a box in my shed in case anyone after I die wants to put it back on. I have the Redline Weber 40 kit on my car with the Petronix distributor and coil, a whatever electric fuel pump and regulator. I still have the stock cam and it runs great. I originally put a 009 distributor but the curve on the Petronix suites the conversion much better. Let me know and I can send you links to all the parts you need for pretty much a bolt on conversation.

Hi there jdamiano. I for one would certainly like to have those links, I'm sure they will come in handy in the future. If you could add them to the post here that would be great, or email them to me at lockwood107@gmail.com. Thanks, Doug

You could always go aftermarket EFI...



This is a kit for a 356. If you already have carbs, you can bold this on a 914 in a few hours. The only thing you will have to do is to extend a the power lead and the O2 sensor lead, and weld in the O2 bung. It will start and run out of the box, but it will need tuning because this is tuned for a 1800CC 356 engine.

I have driven a 356 with this kit. It starts with the turn of a key, it idles great with no issues, and it out performs the exact same car with carbs on it.

Check it out here: https://www.allzim.com/store/356-parts/efi-...ersion-faq.html



Or call Aaron at 800-356-2964 or 817-267-4451 for more info.

I know Aaron is working on a kit for a 914 that will use the original throttle body and runners. But it is not done yet.

Clay

How can you not like this setup?

Budget $$?

The 356 kit is $3495. Plus any options not included in the basic kit.

@bmtrnavsky
to the OP -

i am guessing the impulse sender he is referring to is the MPS the round silver thing, probably was shot when the car was parked. You can rebuild it with a kit from Tangerine racing or source one from someone here, or Jeff Bowlsby will rebuild yours and tune it for factory setting, you will fine tune it- read PB Anders--- Jeff makes new FI harnesses and the alternator harnesses from him or 914rubber.

IF the FI points plate is bad , there are some out there, i have several, someone will sell one to you, and you can put a Petronix or Compufire electronic points module in the top end OR just spend $400 get the 123ignition distributor and eliminate all of that.
new CHT sensors are available, good functioning AFR are out there.
Get all new vac hoses from Dr914- George at AA and all new fuel lines, new spacers and seals, throttle body gasket and intake runner gaskets., your injector seals should be replaced too, .


I am in the keep the FI camp on this one, and to say that parts are hard to come by for the d-jet system is just not accurate anymore at all! there is not one part for my 2.0 d-jet that you cant get new or NOS or reman. its old so what ever you do you will need to clean your tank and lines and get a new pump and filter.

when i bought my car 12 years ago, all it needed was clean tank, new lines and a new MPS, it fired right up. took less than a weekend, all the information i needed was right here on world or in the Haynes Manual and PB anders site.

So YES you can spend less than $1500 and replace all that with new and refresh your motor drive it and enjoy it.
FI once set will be less maintenance than the carb solution, been there done that got the t-shirt.

As for after market EFI, I was looking at these:

http://www.sdsefi.com/specific.html

and

http://thedubshop.com/dual-throttle-body-f...gnition-type-4/

Ethan from Jacksonville Florida aka bearfoot garage on youtube has done a
Haltech EFT conversion.

Phil

LOL... the "Idle up valve" that SDSEFI sells is a Ford Pickup fuel tank switching valve. I put them on 914s with stock injection to idle up the engine with the AC running.

This is always the best solution but comes with a steep learning curve, especially if you dont have someone that knows what they are doing tuning it for you.

Marios kit (thedubshop) should get you 90% of there way there. PMB (@EricShea) has had the other parts needed machined up for a 100% bolt on solution, not sure if they are selling kits stand alone yet though or only installing them in shop.

Brand new EFI is always the best choice but comes with a cost.

Note I am successfully controlling idle in my 2L DJet/Microsquirt conversion using ignition timing only. Works great, drops down and nails it right at 900 every time.

I don't think you need an air valve.

Carb kit. Use the 40s for a stock motor.
http://www.redlineweber.com/carb-kits/auto/porsche/

Distributor
https://www.amazon.com/Pertronix-D186604-Fl...C213&sr=8-3

Coil
https://www.amazon.com/PerTronix-40511-Flam...9BO4C&psc=1

Fuel pump. You can go with any pump and regulate it to about 3.5 psi but Tangerine Racing can set you up with the pump bracket and I suggest a new steel line if you still are running factory plastic.
http://www.tangerineracing.com/stainlessfuellines.htm

I think I got it all. I think the beauty of this is 12 volts to new stuff and you are running. Eliminates all the old complicated stuff.

Let me know if you need any additional information

My advice on carbs:

1. Don't oversize. 40s are big enough for a stock 2.0 L.
2. Go with Dellortos over Webers.
3. Use a good rotary fuel pump calibrated to 3.5-4.0 lbs. of fuel pressure.
4. Make sure your intake gaskets are not leaking; replace if needed.
5. Buy a snail type balancer (NOT a unison).
6. Don't starve the carbs for fuel- go with big enough main and idle jets. It takes experimentation.
7. Do not exceed 30-32 main venturis, or you will have off the line problems.
8. NEVER use ethanol gas.

Ansbacher

If you end up converting to carbs, and decide upon the CSP linkage, this McMark video might be useful for maintenance. Good luck with your choice!

https://youtu.be/ZS3oNSwkUPk

Once you read up on how the stock FI works and how to troubleshoot, you may find that it’s cheaper and easier to fix the FI issues than switching to carbs. If I can do it, anyone can.

And it is kinda cool. So much easier than later versions with all the sensors all over the place. Just a temp sensor/CHT, TPS, and MPS really. Damn thing can run when all of those are messed up too. Not too well, but it will still get you home.

Ok it’s bad trigger points the thingy under the distributor that has gone bad. If I can’t find those where do I find the distributor that works to stay fuel injected?

nice! good you can keep the F.I.

You've gotten a lot of advice and info here, I'm not going to go over any of it again. If you decide to keep your D-Jetronic FI system, you can find a lot of information about it from my web page:

http://members.rennlist.com/pbanders

Note that I haven't been able to gain access for several years to update these pages (can't get anyone at rennlist.com to respond to my requests), so parts that I list as available may no longer be available except from eBay or classifieds. But you can still learn how the system works, and how to debug most problems. Good luck.

https://123ignitionusa.com/porsche-912-914-...ncludes-spacer/

Agree, 123ignition. One of the best things I have done for the car. Just put your old dizzy on the shelf for the next owner if they want it.

123 works to replace trigger points?
How?

Yes, the D-Jet version of 123 provides the functionality served by stock trigger points. Works like a champ.

Yep, just put the two leads from the distributor into the pigtail that hooks to your old trigger points. No cutting or anything. No harm and you can always put the old one back on if some fool wants it original.

I have one of these for my 1.8. Can I buy and run a djet system on my 1.8?

You don't need trigger points on a 1.8. L-Jet doesn't use them. Just get the proper distributor for a 1.8 and plug it in.

Clay

Clay
I have the single carb on the engine. Snce I have the distributor , can I buy the djet setup and use it?