ur20v

I have an '89 90 sedan, 2.3 with manual transmission. A day after I bought the car, it developed a problem (or I drove it enough so it surfaced). The car starts to buck violently, lose power for a second. Sometimes it will do it only once, but sometimes it does it alot. Gets worse with the throttle open. This does not occur when the car is cold, it gets more frequent and progressively worse as the day goes on and the engine gets hotter. I am very worried that the engine is damaging itself and the transmission, not to mention destroying the motor mounts.

I first thought it was the fuel pump because I can hear it get higher in pitch the cut out completely right before the near stalling occurs. I replaced the fuel pump and the fuel filter, but no difference. I can still hear the pump cutting out right before this happens. Anyone have any ideas?

A couple of things to note, which may or may not help - When I go to fill the car up, the cap hisses for 5 or 6 seconds. There is alot of built up vapor in there. The previous owner replaced the filler neck and tank recently, did he forget to connect something?

Second, the ambient switch is missing one of it's spade connectors (broken off - getting a new one Saturday). I don't know if this has anything to do with my problem or not.

Third, the crankcase breather hose is collapsed on itself. This hose looks like it has two different sized ends, does it? Dealer only item?

I opened the relay and it's in fine shape, no cracked or broken solder joints, broken or burned connections. But since it does control the fuel pump...

Any insight? Anyone ever experience this?

Julian_B

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ur20v

It's so bad... the car lurches and bucks violently - like the negine is going to tear itself right out of the car!

ur20v

I went for a drive down the street, and sure enough, the car started acting up again, very soon, too. So when I was leaving the store, I unplugged the O2 sensor and the problem persisted. I don't think it's the O2 sensor, but, my testing method could be lame.

YucatanAudi

You can make your own crankcase breather tube out of various hose and plumbing parts or you can buy the metal replacement version from the dealer. Either way, until you fix that, it's not going to run right.

3) I wonder if you have a plugged vent or vacuum issue with the gas tank. Sounds like it is starved, then gushed with gas. That would really make it buck. THe only thing I know to tell you there is to have an Audi-smart mechanic check it, or get a Bentley manual and examine the diagrams.

4) Have you checked the fuel filter and fuel accumulator? These are near the passenger rear wheel under the car, with the pump. Try changing the filter (replace washer seals).