replacement of my fuel pump or filter

I recently started having problems with my 1988 Audi 80 quattro. Until last week, I had never had a problem with it. Aftter returning from leave, my wife and I were driving the car - when it just died while
running. I tried several times to re-start it, but it didn't start. Twenty minutes later it started without a problem. I thought it was BAD gas, so I added some dry gas to my fuel --- it ran fine for several days. However, yesterday the car stopped again, I had it towed home and left it in my garage for the last several days .... ony now it won't start at all.
I'm not sure whether it is the fuel pump, fuel pump relay or the fuel filter. I have just purchased a new fuel filter, but; I'm looking for help with this problem. In addition I'm not sure of how to replacement the fuel pump ... if in fact it is the problem. I have heard that the fuel pump on the 1988 a80 quattro is submerged in the gas tank.
Can anyone help me with this problem:
Tks in advance
snipped-for-privacy@acsalaska.net.
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The problem might be from a number of causes including the fuel supply that you suggested. Have you determined that you have spark to rule out ignition issues? These could be caused by failing hall effect in the distributor, loose ground connections, failing ignition switch ...
If it is fuel related it could be a number of issues but your thought that the problem is with the fuel pump relay is quite likely. The fuel pump usually dies slowly (months) and makes noises during the process. Old fuel filters usually cause bucking when the engine is under load.
When the fuel pump relay it is usually as you describe - all at once and kills the engine. The relays are also known to have intermittent failure as you have described. To test you could replace with a known good relay. If you don't have a spare you can connect a jumper wire across the larger terminals when the fuel pump plugs in to the relay box. If the car starts that is your problem. You can actually drive ti this way but I would advise against it because the relay shuts off the fuel supply in case of an accident.
mrd wrote:

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I don't know whether or not the fuel pump is submerged on your car but I would place my bet on the fuel pump relay in your case. I had an Audi 80 from 1987 before and i experienced what you have now except my car never went totally dead. If I started it and drove away it would run just fine for a few minutes and then suddenly die. If I waited a few minutes it would start again but only run for a few minutes and so on. My car wasn't a quattro though so the search for error was easy since the fuel pump was located under the car just inside the rear right wheel together with the filter.
/Stefan
mrd skrev:

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Mr. D, If you've been hearing what sounds like a nest of bees in your gas tank or under the passenger side of the car, then it may be the fuel pump. Considering that you don't know where the pump actually is, well, that's an indication of it working OK. I would check the fuel pump relay - possibly bypassing it to test if the pump comes on. I had a flaky relay on my 5ktq and it would occasionally cut out while turning or driving, sometimes wouldn't start, etc. There was a hairline crack in one of the internal solder joints - I reflowed the solder and it has worked like a charm ever since (maybe it's scared of the 4 relays I keep in the glovebox as backups as well?). Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)

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