John_Hatton

Hey Everyone,

I'm fairly new to the forum, and before I finish, I am very very new to fuel, and fuel related issues, especially in relation to no start. I've wanted to do a thorough write up, but I needed to do my fair share of googling, and personal research, so on... Please, if you find something on google, I know I am dumb, I probably put in the wrong search criteria, but please don't give me lip about how I haven't googled enough. ;D Your help would be greatly appreciated!

I made a post recently about my newest purchase, a 1991 Audi 80 B3, about fuel-pump location. Well I found it. It's in seemingly good condition, for a car from 1991. Only about 160,000 miles. The biggest downside is that it has been parked for the last six years. The wheels are almost done for, and the brakes need some overhauling, but they'll work for now. The bigger problem I'm having, is that the car won't start. I was able to remove the hose, off of the exhaust manifold, to spray starter-fluid up into the engine, and it would run on starter-fluid. So that rules out any electrical or ECU problems, right?

I got a new battery, and put the key in the ignition. When I primed the key, no starter noise... I thought, okay, the fuel pump could be bad... In the end I replaced the fuel pump, however, as they say, a failing fuel pump usually takes the fuel pump relay with it. I replaced the fuel-pump relay, of course in the beginning, after testing first the fuel-pump fuse, which was good, and then testing the pump relay for resistance. I inserted a makeshift bypass, the fuel-pump would not kick on, so I replaced it. I also replaced the fuel filter while I was at it. Now, when I turn the key, the fuel pump primes, just as it should, and everything seems to be working perfectly from the back end of the fuel system. The tank reads correctly, with the gauge and everything, and after loosening one of the fuel lines right here:

I have many questions, but I'd like to finish my diagnostic process. Happily with your help, of course!

The first, and most important question is, where is my Schrader valve, where I can hook up some sort of fuel pressure gauge? Must I install one somewhere?

Second question, I've got a copy of the original Audi Repair Manual, for the B3, which includes the 80, 90, and Coupe versions, and their corresponding Engines. However, on the page, where it shows that I need to attach a fuel pressure gauge to test for failing fuel pressure, I cannot see where the connection could be made, the picture is super low quality from 1991 or whevener it was printed... I removed the exhaust manifold up and out of there, and I want to see where things are at, in relation to the pictures in the Repair Manual. Anyways, my question is, which of the following items could be causing my no-start issue, and what advice do you guys have, to get this thing started?

-Fuel Accumulator? (I'd like to conclude that the fuel accumulator is working properly, because I'm getting fuel up to the front of the engine, past the fuel filter. (The line goes from the tank, to the fuel pump, to the fuel accumulator, and then the fuel filter. Then on to the front of the car. I'd have to test for pressure drops to be really sure, right?))
-Fuel Injectors? - This one is still my biggest suspect, but I don't want to just go spend $150 on new fuel injectors, when I could clean them, or otherwise repair them. Is that worth it, or should I just throw more money at the car? xD - How can I test for failed fuel injectors, and what options do I have, to clean them, and get to them. They're all kinda hard to get to...or is my problem likely something else?
-Engine Computer? - I also am a bit suspect about this one, because it's got timing working right, so the engine is firing. However, perhaps it's not regulating the EFI system properly? Like I said in the beginning, I'm totally foreign to EFI, and really fuel in general. I appreciate your schooling me in advance! My only other slightly unrelated question here is, is this car (presumably) OBD-I, and is there some sort of diagnostic computer, that I could plug a VAG-COM device to? I owned a B6 once upon a time, and so I know Audi has been properly equipping its cars with computers, I just don't know what my options are, since it's pre-OBD-II.
-Timing Belt? - Is it possible, that the timing belt has slipped off a few teeth? I'm thinking highly unlikely, also, because the engine fires with starter fluid... but well, thoughts?

Guys, I've essentially exhausted myself on this car, and I need your help. I'd like to start testing some of the other systems on the car, and making appropriate repairs, but I gotta get this SOB started! Thank you so much for reading through all of my research. I hope with your help, we can get this beautiful car started!

Sincerely,
-John Hatton

2ducs

You don't have EFI. It is mechanical fuel injection. Also it prob needs the injectors cleaned as well as new o rings on the injectors. Lastly make sure you have fresh fuel.

Audi90finesse

I am as well a newly acquired, low mileage, 1988 Audi 90 b3, with the EXACT same issues, same diagnostics, same questions to a T. I've replaced everything but the fuel filter but I know I have fuel at the line, can't find the shrader valve. Starts with fluid, has spark. One thing different is or an addition to, when I crack the line going to the cold start valve, I see that there's fuel saturating from the start but nothing on the banjo nut. And none of the inject lines arent getting fuel, but crack the to and return line and they are as well saturated.

Also I bought a new battery and it doesn't seem to hold a charge past cranking it 5 to 6 times.

Have you made progress?