1984 Audi 4000 1.8L

Hello,
I have an '84 Audi 4000 1.8L fuel injected car that has "fuel delivery" problems. It will start and drive for up to 5-10 minutes
until it starts to loose power, sputter and hesitate and finally stall. While these symptoms are present, trying to use the accelerator actually seems to make the symptoms worse. For example: your stopped at a light and try to accelerate. This is when it will ususally stall out.
My local VW/Audi/BMW mechanic cleaned some gunk out of the fuel pump and I drove the car for 30 minutes until the symptoms returned. My mechanic says that he is not sure what it is and if he starts replacing parts it is going to get expensive. He has "confirmed" that the fuel pump is working at least when idling but not while the car is being driven.
So, if you might have any suggestions to offer or might know someone who knows these cars I'm all ears. Thanks in advance for your attention.
-Chris
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Does it immediately start back up?
Did you mechanic do a fuel pressure test on your vehicle? Did he check the current at the Fuel Pressure Regulator? Might be a bad ground......located at the cold start valve IIRC. ******A lot of times I find that someone removes the fuse to this part of the system thinking it is a spare fuse.****** lol
Is the fuel filter new? There should be a container near the fuel pump that is installed in the fuel hose/line from the gas tank to the fuel pump. Maybe it is clogged. Usually the pump complains about a lack of fuel by Whining louder.
Maybe there is a serious vent problem and vacuum is created inside of the tank. Try taking off or loosening the gas cap to see if that stalling changes.
3 things needed: Compression Fuel Spark
later, dave (One out of many daves)

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Dave,
Come to think of it, I did replace the fuel filter 6 to 12 months before this stalling began. I'm no where near a mechanic so anything is possible although I was careful to put the filter flow in the correct direction. The pump does whine a bit but I can't say for sure if it has gotten louder. I'm not sure if he did a fuel pressure test or check the fuel pressure regulator.
The cold start valve IIRC is located where? And the fuse is located where? I'll check the fuel filter and see if the gas cap technique helps out. I really appreciate your input on this.
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The fuel filter should be after the fuel pump. The part I am referring to is a plastic 'reservoir' (for lack of what it is truly called) and is before the fuel pump or between the tank and the pump. Maybe yours doesn't have it but if it does maybe it is clogged up some.
Fuse is located in a bank of fuses towards the left side of the fuse box. The fuses are all in a row and can look like "spare" fuses. If you take them out you will see that some of them actually have terminals for the fuses, but some won't. ;-)
The cold start valve is located on the intake manifold and will have a braided fuel line coming from the fuel distributor going to it. Sometimes the grounding wires there vibrate and break leading to a problem with the fuel pressure regulator.
later, dave (One out of many daves)

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Dave, To respond to your first question: no, it doesn't immediately start back up after stalling. I need to wait a good 45 minutes to get it going again, usually. The stalling symptoms usually appear immediately after I start the car back up after a 45 minute period. If the car sits about 12 to day it will start back up and drive but the symptoms will appear in the 5-10 minute range.
Thanks, Chris
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I mis-posted this in another thread. Bad connection with my Qwest DSL for last week may have delayed a thread loading or I may have just screwed up. Anyway >>>
In an earlier thread about an '86 T44 I was suggesting that the problem was the fuel tank lining peeling off and clogging the fuel pump intake screen intermittently. I would think that this may be your problem too.
Fix: -cut intake screen off pump and replace fuel filter more often.
You might also have a weak fuel pump relay.
youngc wrote:

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Tony,
Thanks for your suggestion. The fuel pump intake screen is located where? On or inside the pump? The pump is directly hooked up to the fuel filter then going to the gas tank. What is the job of the fuel pump relay? Just curious.
Many thanks,
Chris
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If it is like the Type 44s in that time the fuel pump is located in the bottom of the fuel tank and is surrounded with a mesh screen to filter the fuel before it enters the pump. If the tank is shedding its inner lining the bits coat the screen and impede flow to the pump. Correction requires opening the tank and removing the pump to cut off the screen. Really not too bad of a job if a bit messy. If you aren't into DIY a local independent audi mechanic could handle it easily.
Fuel pump relay turns power on to the pump when the engine is running and in some cases when the ignition switch is turned to the 'on' position. If the computer sees the engine stop running it tells the relay to stop pumping fuel. This is a safety feature for possible accident situations. Relay is likely to be located in the main relay box that is probably under the hood.
youngc wrote:

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Tell your mechanic to test the entire fuel process; from the fuel tank to the fuel injectors, should take a couple of hours, and make sure all hoses are connected that need to be connected, unlike one of mine which caused all my various problems :-)
Chris
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cp,
Thanks. He is a bit hard to communicate with but I will prevail.
--Chris
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Find someone else. If you're in the Vancouver BC lower mainland area (most likely not) I can pass on the number to a very patient and reasonable mechanic.
cp
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