I was cruising along in my 00 Z28 A4 about 70 mph when I felt something like a small bump, but it was from the enging shutting down for a spit second and coming back to normal. All the lights lit up on the guage cluster and the guages did a sweep just like during startup. The lights went off one by one just like start up too. I am suspecting a loose wire somewhere or the ECM rebooted quickly for some reason. Has anyone seen something like this or can offer any other ideas and suggestions? The car is stock except for an SLP pulley, air lid with K&N, free ram air mod and a Flowmaster muffler. Thanks in advance.

 

The bump part happened to me on an 89 Formula 350 I used to have. Engine quit, immediately came back. I even wondered if I imagined it. Later it wouldn't start and I smelled alot of gas. Then it started right up. Got worse later, both banks flooded. From the wiring diagrams saw only thing that could do that was the ecm, so I dropped it down and smacked it with engine running. Engine burped. Smacked it hard and engine died. Replaced ecm, problem fixed.

Posted my experience in third gen section, one guy responded that he's heard of it happening more in 4th gens, probably due to their higher heat location. So if wiring checks good, try smacking the puter to see if it skips.