v8guy

I have been trying to get '87 5000 CS Quattro to start for weeks. The head gasket went a few months ago and now that that is all fixed it has no fuel pressure to the injectors. I jumped the relay and pulled up on the air meter while cranking and still no fuel. The pump and relay are good. I have pressure coming in from the fuel filter to the fitting where the cold start injector supply line is. Now, as for the two lines for the differential pressure regulator, the one line that is next to the pressure relief valve has no pressure at all, and the other one has a little bit of pressure coming from the fuel distributor but not much. If I disconnect the line entirely and jump the relay fuel will pour out of the fitting port in the fuel distributor, but the pressure is so low I can block it off with my finger. Can anyone help me with this? Also, how does the fuel distributor actually work? Is there a FAQ on this anywhere? I know a bit about electronic fuel injection, but not this crazy thing. Please Help.

allaudiguy

Had the same problem with one of my cars, stood unstart for a few months, anyway , to make a long story short, i also did all the checks you did , and lastley i unscrewed the injectors and took them to a friend who blew about 4 bar of air through them , seemed they clogged up, dont know why, can be old feul or what ever, washed them clean, also flushed the injector lines from the distributor to the injector out with some carb cleaner, that solved my problem, try it, might be whats wrong there with yours.

Albie
91 500 Turbo 10v
South Africa

v8guy

Cool, thanks Albie. Right now I am getting no pressure out of the distributor when I take an injector line off, but I'll probably flush the lines and blow out the injectors for good measure once I track down the heart of the problem.

v8guy

I simply don't have enough pressure to open the injectors. Pulling up on the air valve flapper increases the volume but the pressure is very low. I have high pressure coming in from the pump and high pressure coming out of the fat line that goes to the regulator??? From there there is low pressure going back to the tank and high pressure going to this other dohickey that looks like a normal fuel injector. From there it goes back into the fuel distributor, but the pressure is low. Jumping out the injector thingie increases the flow a bit but pressure is still low. What gives. CIS = CAR IS SCREWED!!!!!!!!!!

tonyj

on the front of the fuel distributor (three wires). these go bad on occasion. Could be that it just needs to be unplugged and re plugged in to clean contacts.

v8guy

The differential pressure regulator on my engine is bolted to the block on the driver's side. It has very slight pressure going to it and none coming back. Shouldn't full pressure be going to it from the fuel distributor?

v8guy

I took apart the fuel distributor, blew it out with compressed air, and put it back together. Now I have pressure to the injectors. Yo, that thing was no joke. Getting those six o-rings to stay in place around the little ports during re-assembly was fun.