Hello,

I recently bought a 1973 Porsche 914 with a 1.7 and fuel injection. The car ran ok when first purchased, However, I went to start the car, it would not fire up. Got spark etc, but no fuel. I noticed most of the fuel injection wiring harness is brittle and or have cracked wires. I have tried cutting out the old wiring where I can, however to no such luck.I would like to keep the car fuel injected, however, I can't find where to buy a new wiring harness and or don't want to assume that is the only cause.

I recently have been discussing with other past owners of the 914 and two have said to go with Dual Weber 44's or 48's? if I went this route, do I need to change out my distributor and Cam? I know the fuel pump will need to be replaced.

I would like some input and or advise from someone who may have already traded out the fuel injection for carbs.

Lastly, Im an old VW guy and know carbs but the wiring on this fuel injection seems it could take me down the rabbit hole to more problems and cost.

Thanks

Mark

From someone who loves running carbs this is what i would do.

1. Contact Jeff Bowlsby and get a new fresh harness
2. Install harness and continue to diagnose - tons of help and info out there. FI can be difficult but with a methodical approach you can replace each piece to diagnose the issue.
3. Throw in the towel so you can drive the damn thing and purchase a set of weber 40s, 44s on a 1.7 will need to be choked down a lot.

I also have a 1973 1.7 ... and I also come from the VWs.....
I had to get used to the system but it is actually a really interesting and good thought out system. Try to solve the issues first.
If you go for carbs....that saves a lot of injection issues for sure (duh) but 40s are large enough. Good luck with your 914 ! Welcome.

I would keep the FI if possible.

The stock cam in a 914 is not good with carbs. It will get lousy gas mileage, poor performance, and you will have gas smell in the car from the open evaporative emissions system. Plus, you will have to choke the carbs down a bunch to get them to work. Lots of changing venturis and jets. And if you go up and down mountains a lot, you will be constantly re-jetting the carbs.


The D-Jet system is dirt simple for a fuel injection system. Lots of people on here can help you troubleshoot it and get it running. And I agree with replacing the harness first. Jeff's harnesses are da bomb and will save you hours of troubleshooting.


Or you could go with a megasquirt system. Use the stock intake parts, replace the injectors with megasquirt compatible and hook the harness up to the existing sensors. There are even people on here that will give you a base program to upload to your MS. Then use tuner studio and an wideband O2 sensor for the self-tune program.

My $.02 Carbs - No. Stock D-Jet - Yes. Megasquirt - Yes, but expensive.

wrong cam (requires rebuilding the motor)
wrong distributor
wrong fuel pump
and 44's, or 48's are way too big for a 1.7

I think 40's may actually be too big, but can be choked down to make work.

If you go to carbs, you will lose horsepower unless you also disassemble the engine and install a new cam that is better suited for carbs. Then you will spend hours tuning and jetting the carbs to cure the inevitable flat spots and cold starting problems. You will also need to replace the distributor with a 123 unit to get maximum power from the carb conversion. Search all the threads on this forum about people trying to get their cars to run properly with carbs . Much easier to replace the FI wiring harness with one from Jeff Bowlsby or rebuild it yourself. The Djet FI is a very simple and unsophisticated fuel injection system compared to modern ones. You can do most of your troubleshooting with a volt ohm meter and a vacuum pump. No need to buy a proprietary computer program from Porsche or Bosch to read and clear “check engine lights” and codes.

Just say NO to carbs!

No. KISS.

1st off i love carbs but ...


Youre at a crossroads, ive been there before

You cant just go to carbs . unless you use a set of baby single throat webbers . those bolt right on and while not perfect .not bad . my opinion also need fuel pump

But to really do carbs . 40s and up you have to rebuild the engine to take advantage . plain and simple

You could do djet . but 1st find a witch doctor to help .
And its no longer reliable because its fuckin ancient
Not because its not a great system .

So if you can afford . build a killer carb engine .

If not the others will be more budget friendly but not as spunky.


I would put baby webbers on my 1.7 in a second ( djet also starting giving up) but i lucked my way into a big /4

So thats what i would do

Here is my website if you decide to keep the FI.

https://bowlsby.net/914/WiringHarnesses/

with all comments,end of the day by the time you buy carbs and all you needed parts you could bring the FI up to standard and have a better running driving car.

44s are to big you would run rich no matter how you jetted them. I can’t speak directly to the 1.7 but I love my carbs on my 2.0. I got the Redline 40 Weber kit with a Petronix distributor. Any loss in power is offset with reliability. It’s less complicated and brand new. I would stick with EFI if you want to maintain originality or aren’t willing to buy all new parts for your conversion to carbs. I have all the EFI in a box in case the future caretaker wants to put it back on.

Totally agree with all the comments. When I switched, 1981, it was the thing to do, know one new how to trouble shoot the FI system. I was stranded many times on the side of the highway with the FI, that is why I switched. Car had 75k miles. Put another 70 on the car with the carbs and was never stranded, but it did not run as well and got less MPG. Now it is rebuilt into a very nice street 2056 and the carbs can finally sing like they should. The guys at Tanagerine Racing did a great job on it.

I was there once upon a time, I stuck with FI and I am glad that I did - once I got it running correctly (took a while) it is a stock car with dozens of experts. If you go with carbs you are trail blazing - very few people will have your setup.

If you stick with the FI, grab the plenum and make certain it is tight - this is the source of countless trouble when addressing the FI systems.....then the MPS.......

GOOD LUCK!

CTC911CTC

it is a stock car with dozens of experts.

CTC911CTC
[/quote]





You heard the man
................................... Dozen of experts...


So if your f.i go's down there are about ...12 guys in the world who can fix it .... Id say thats about right ... Its unfortunate but its accurate. Ask 12000 mechanic s about djet . 1 of em may be able to help

I'm not at all anti-carb...but:

Since your stock FI is mostly complete, I would recommend sticking with it as it is the best bang for the buck solution for a stock engine with a stock cam.

I've got a stock 2.0 D-jet system on a 2056. I put about 8,000 miles a year on my car. The system isn't perfect, but I find it highly reliable for a street engine. Once you get it tuned, you just drive it. I haven't had to do anything mechanical to my engine in 2 years - haven't even tuned it up and I just drove it 750 miles in 2 weekends.

There is a bit of a learning curve, but worth it in my opinion. This resource will supply most of the info you need:

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

While written for a 2.0, many of the components are the same.

At one point, parts prices became prohibitively expensive (particularly the MPS)...but over time, as demand rose for FI parts, solutions have been found.

Start with a wiring harness from Bowlsby and go from there. 1.7 FI parts aren't too hard to find.

Let us know what you decide.

[quote name='thelogo' date='Jul 27 2020, 09:22 PM' post='2837708']
it is a stock car with dozens of experts.

CTC911CTC
[/quote]





You heard the man
................................... Dozen of experts...


So if your f.i go's down there are about ...12 guys in the world who can fix it .... Id say thats about right ... Its unfortunate but its accurate. Ask 12000 mechanic s about djet . 1 of em may be able to help
[/quote]


There are lots of D-Jet experts out there. It was used on everything from Mercedes, to Volvo, VW, Audi, all the way to the Chevrolet Cosworth Vega. So there are people out there that can help fix it. And it is dirt simple, so you can learn how to repair it yourself. It is not rocket surgery.

Carbs are like doing accounting with a pencil and paper.
D-Jet is like doing accounting with a mechanical calculator.
Current EFI (megasquirt) is like doing accounting with Microsoft Excel.

The accuracy and efficiency goes up with each new improvement.





Clay

Better yet put a Subaru in it.

Welcome Mark! Lots of us here in SoCal.

Troubleshooting any FI system requires a methodical approach, if you aren’t up for that make the switch since you need to be able to maintain the car (and a non running car is no fun).

I’d personally give it a go with the FI, read the materials provided before making any decisions however.

not in a million years. PLUS 44s are for racing only and 48s do not belong on any 914-4

My $.02 worth...
I bought my car in 1995 with 40 Dells, ran just ok, lots of gas smell and crappy mpg. Sourced a complete FI setup and in '98 junked the carbs and just figured out the Djet including tuning it. Since then the car has had me stranded once, in my driveway as the CHT died so it went full rich so no start.
Nowdays I have a 2056 with a better cam and big valves so it goes faster but still it is rock solid dependable. Hooked up all the fuel vapor stuff again so no gas smells which my wife loves.

Well said.

Modern EFI is already well beyond Megasquirt EFI with gasoline direct injection and small turbos producing high power density and high durability out of 2.0L engines that are making 250HP / 275 lb-ft of torque that would be unheard of out of a VW T4.

Love modern powertrains but there still is nothing like the clatter of a vintage air cooled engine, induction, and fan noises for me.

I think there's a component of keeping any older car sort of original if possible. Wife has a 77' T1 and the L-Jet is pretty easy to diagnose. CIS is even easier. Most of the time it's a vacuum leak. Some hose with cracked ends or one that literally popped off etc.

Difference between FI and Carbs:

When FI breaks you stand there scratching your head. When carbs break you open your tool box and fix it on the spot. It's kind of like the stock market. If you can tolerate risk (being stranded without a clue as to what is wrong and how to fix it) then FI is for you. If you want reliability (with a slight loss of return) then carbs are the way to go.

Ansbacher

I love opinion pieces.

I went from a functioning L-Jet system to 40IDF carbs on a 1911cc. Last year I went back to the FI. It just ran that much better. Better fuel economy and zero hassles. I'd stick with the FI. Get it working and you'll be happy you did.

If you want carbs I'd go with a pair of 40IDA's, and the flat six that comes with it...

I had the same problem with my '71. The 4 white wires on the rear outer corner of the relay board are ground wires one of them being for the fuel pump. The wires ground on the engine cases. CLEAN the ground wires and the fuel pump might work. I've found most of the electrical problems on my car are from bad ground wires.
GOOD LUCK & KEEP THE FUEL INJECTION
You can always call Auto-Atlanta for help, they are always willing .

I mean im not on pelican but i dont think you
See may guys with djet on there 356.s
Arguably best car porsche ever built !!!

Only if you don't understand fuel injection......

D-Jet didn't exist when the 356 was in production. And they have one at Zim's right now that they are fitting with replacement throttle bodies and megasquirt.