Fellas:
On the audi 100 wagon that i just picked up, i am having an acceleration problem. I basically sat the car in the garage since its purchase. The p.o stated that the car had a difficult time going in reverse after the car came up to operating temperature which i was well aware of. I put the car in the garage changed the oil and spark plugs, just to see how she sounded. With 165k on her she sounds pretty good. Today I took her around the block and it began to stumble over 30 mph and accelerate slowly. This was kind of strange, and the fuel pump got louder than normal.(ITS ALREADY EXTREMELY LOUD The car felt kinda fuel deprived. It was a stumbling type of very slow acceleration. Now when the car was in park, it would rev very freely, but on attempted accleration, it was slowly acclerating????? I knew the situation with the reverse gear on the tranny, and dont think they are related. BTW. the reverse gear does work fine until it warms up, and all the forward gears are good. One of my MB's had a similar problem and I believe the reverse pak was bad in the tranny. The audi kinda feels like it has sat for a while with bad gas....... things that make you go HMMMMMMMMM

I have not changed the cap,rotor, or wires as of yet

BTW:
I just stopped out to the garage and started the Audi. I kept the car in park and it was kind of "puttering" like it did when i drove it earlier. After 3000RPM that's wjhen it did the symptoms.

Did you change the fuel filter? If you suspect that it is the fuel pump then do a flow and pressure test. Measure at the return line, you should get approximately 750cc @ 12Volts (pump voltage) system pressure should be 88 - 94psi.

You also need to check the ignition timing and belt. If your belt skipped a tooth or two you will have drivability problems. Automatic transmission can have problems that sometimes feel like engine problems.