porschelover98

Hello everyone . I haven't posted here for a long time about my car. I have my 1983 Porsche 928S "Euro" which I have been restoring for around 3 years now... Yup, that's a long time, but as I stated earlier in other posts, it's near impossible to restore such a car where I live, and I have nothing I can do about it. Anyway, I technically got the engine to run, but there was a catch. Now I used to have a problem with my old fuel distributor that it loads way too much fuel to the engine, causing the engine to sort of "drown in gasoline" which caused the car to barely run in the first place, and when it does, it runs very sluggish, and then turns off when it likes to. So I got a rebuild kit, and got my mechanic to rebuild it, (There is no one available, or willing to rebuild the distributor except for him), and after the rebuild, it worked fine for a very short period of time, then the same problem happened again, oh well. So I purchased a rebuilt distributor from the U.S.A. and was surprised to find out that the plunger was stuck, I contacted the seller about it, who told me to spray the plunger in WD-40, and try to move the plunger using plyers, which worked perfectly, he helped me out a lot, I couldn't have done it without his tips. Anyway, so I install the distributor on the car, but the distributor was refusing to get any gas into the engine, zero, not a drop, which was weird, because the distributor has been fully rebuilt as I was told, and I had no doubt about it. It seems brand new. So now, I am stuck with a rebuilt fuel distributor which I cannot return (although the seller offered me that) because the shipping costs will be as much as buying another distributor. I checked the fuel lines leading to the front of the car, which worked flawlessly, and I tried pouring gasoline directly into the mass air flow. And the car ran like a dream. So what could the problem be? The distributor? Which is unlikely, or the mass air flow sensor, or what? I am bewildered by this whole issue. Does anyone know, or has an idea of what I can do? I would greatly appreciate it.
Thanks all.

A quick general update about my car: I have replaced basically everything in this car, and if anyone wants to know the list of parts I changed, tell me so I post it if you guys wanna see that. Cheers.

jpitman2

CIS is all controlled by pressures, so you need to get a gauge set, get the pressures and come back. System should be around 75psi, cold control down < 20psi @ ~15C, going up to 45psi hot through. Flow rate should be around 1350ml/30 secs at the return line over the cam cover. Get a copy of Ben Watson on Bosch injection - good on CIS, and troubleshooting. If control is high(with pump jumpered), crack open the WUR outlet(safely) - if pressure doesnt drop, its blocked- very common problem. Hot control >50psi will run, but very little power or response. Search other threads on CIS here.
jp 83 Euro S AT 57k

porschelover98

Hello Mr. jpitman2, thank you for this very detailed valuable information. I will check it out and post about what happens.

Peter Tavares

Did you check the fuel pump relay, is the fuel pump at the back of the tank (you call the distributor) actually energizing(can you hear it spinning immediately after the key to the ignition is turned. It will time out after a few seconds so you need to have a friend turn the key while your at he back to listen if it's making a sound, If it is it's bound up again or not getting power(chk relay). If it was along time since car hasn't run and you did not drop the fuel tank to clean it out and merely just reattached a new fuel pump it would only take seconds to suck any contaminant back into your new fuel pump once again binding it up. Remnant gas will turn to varnish and if that flows into fuel pump, game over.

porschelover98

Hello Mr. Tavares. Thank you for this info. I have replaced the fuel pump well before I got the engine to run. And cleaned out the fuel tank completely, and got it back to the car, along with the new fuel pump. Which also works perfectly, as I heard it run once I try to run the car. I also still checked the relay, which seems to work too. I connected the car to an external seperate fuel source, which didn't do the trick, and checked if the fuel flows to the front fuel lines which connect to the distributor, and it works perfectly. So the fuel is out of the question as it is all A-Ok. My mechanic says that there is a type of "seal" that is inside of the mass air flow, which probably is the main issue of why the car is not running. I will replace that part and see if it works. I did jumper the mass air flow, and I got zero resistance, and I did not hear the injectors start. Which means that this is the main problem with the car.

jpitman2

If pump does not run at turn on, try reversing polarity at the pump - if its stuck due to debris inside, this may dislodge it. I had good result (with a working pump) by loading (ie, more than normal amount) tank with Berrymans or Marvel Mystery oil and bridging the pump relay and let it run for some hours to try to get rubbish loosened and dumped in the filter. Will need to change filter after this. If the proper pump relay has been replaced by an ordinary one you may find it runs all the time. Proper relay will run pump at turn on for a few seconds, then stops until you crank it, and also stops as soon as engine stops.
jp 83 Euro S AT 57k

jpitman2

There are multiple Oring seals inside the FD. The critical ones are the 8 in the moving piston in the centre - they are easily damaged when assembling. There is also a critical pin hole in the steel shim gasket that feeds the WUR. Find a thread here on fuel distributor rebuild.
It might be a help to know where you are.....
jp 83 Euro S AT 57k

Wisconsin Joe

The 83 Euro S is CIS (K-jet) injection. Purely mechanical.

There is no 'Mass Air Flow" sensor in it. That is only present in the 84 (Euro) and up with the LH injection (electronic injection, MAF & engine management computers)

porschelover98

I have checked the pump, and the fuel lines previously. They are all clean and the car runs well, but only if I put gas directly into the mass air flow. Thanks for the tip of course, I will probably also try to flush out the system again. But it is mostly not the problem.

porschelover98

I see. Thanks for the info, I am not very knowledgeable for the injection system. Anyway, my mechanic stated that there is a seal inside the mass air flow itself that probably deteriorated. And he will replace it because he claims that this is causing there not to be any pressure. But I'm not sure I understand what he means about that.

porschelover98

I don't bet that the O-Rings were affected. And if they were I wouldn't really know until I fix the pressure problem in my mass air flow. But if I fix the pressure and it still does not work, hopefuly not, then I will check it out.

porschelover98

Well. I have now checked the following on my car: The accumulator, the fuel pump, the primary pressure regulator (my main focus), the fuel flow from the back of the car to the distributor(again) and still with the same good results. And I have also ran the car with the mass air flow jumpered, which made it run, and all of these things checked out. So now there is no possible logical reason except that the rebuilt fuel distributor may be the issue. Now I may obtain a Mercedes 560SL fuel distributor, which is almost identical, and will try it on my car, if it works, then it's the fuel distributor, and if it does not, then the fuel distributor is not the issue, which is not likely. I will try this and see what happens.