Have a '92 audi 100 2.0E (AAD engine) which has been losing power over the
last few months. When cold, runs fine, but when hot, at idle, the revs creep
up to about 1200 RPM - if the accelerator is pressed at all, the engine
splutters and tries to stall. I've also noticed that the plugs and the
exhaust are very sooty. I'm waiting on an oxygen sensor arriving to try that
but I have been told that a small sensor/valve on a rubber mount close to
the metering head gives trouble. The valve has Pierburg 048 133 517 written
on it - don't have a clue what it is.
Anyone with any advice would be greatly appreciated.