I have been experiencing this for a while now and just can't take it any longer. Under normal exceleration in 1st or 2nd gear the car for what ever reason feels like the clutch is temporarly engaged almost a jerking like when you stall. A while back it just stopped running, couldn't figure it out, broke down and took it to the shop(ouch). Culprit was the Differential Pressure Regulator(DPR), plus put in new plugs, wires, cap, rotor, all belts and fuel filter. Car seemed fine after that. However when the tank got to 1/2 or lower it started again. So I just kept it above that and I drove it very mildly which seemed to help. Now it is doing it even when the tank is abouve 1/2. So, what would cause the DPR to fail? I haven't a clue. Any advice???

 

I doubt that the problem is in the DPR. I think that the problem is elsewhere like in the tank. You either have dirt, water, the pump is on it's way out or the pickup tube has detached. During hard acceleration you are pulling G-forces and the fuel shifts. OR the pump has detached from its mounting and is hitting bottom under G forces. You can get an electric fuel pressure gauge that reads 0-100psi and hook it so that you can see what is happening from behind the seat. I got one from Nordskog Performance for about $100. Using various jigs and fixtures you will be able to determine where the problem is.

 

I dont get it. if you try to engage a gear is like you are not pressing the clutch all the way? or you do able to engage the gear but then even without releasing the clutch its starts to engage clutch? or you engage the gear start to release the clutch and car starts to jork like jumping? or what?

 

The whole clutch reference was just an example of what the car feels like when the jerking or stall begins. Some might refer to it as a sputter.

 

just connect an fuel pressure guage and see while you have the jerking.

 

Well it turned out that the problem was around a gallon of misc sludge in the tank preventing adaquate flow to the pump. Opened tank cleaned micro filter on the bottom. New pump, filter and heat sensor. After this the shop called and said come and get it. So I went and picked it up and it was idling around 2K. Never before has it been that high, But the car was running pretty quiet compared to what I was used to. So I took off down the road. Alas something was and I'm sure still wrong. The car won't go over 3K rpm's while in gear and is making damn near zero power while going up hill. So I rev'ed while in neutral and it made it up to 4K rpm's. I'm confused and so is the shop where it's been at for the last 2 mo. Needless to say I'm really ready to get my car back. I wanted to know what the forum thought the problem might be and I'll give it a go. Thanks

 

Make the shop do a fuel presure test ..... system presure and residual presure ... bad injecteors also are a pssibility (the car is most likely at or over 100K and ijectors have never been replaced) also a good thing would be to adjust the idle (check the Idle Satbilizer Valve) and then readjust the fuel mixtuere ratio .... and do use a Bently manual for this ... also ask around for recomendations of mech shops who specialize on european or beter yet audis