90/90Qs

here's the situation, my car misfires like it has 3 or maaaaaybe 4 working cylinders, I have put it on a scope to view ignition traces and they all seem fine and I believe any problem with the system would be apparent on the scope. I have also built a fixture to view my injectors trigger and spray pattern and they also seem fine. One thing I haven't tested is fuel pressure but I'm curious, isn't it more likely that pressure would be too low (failing regulator)? -If so wouldn't it be more likely to be running lean and have better fuel economy rather than (as it is now) have a major loss of power, poor fuel economy, and terribly rough idle?
-What are the usual symptoms of low fuel pressure?
Given that it <i>seems</i> my fuel and spark are ok, the only reason I can think of for having a misfire now is a crack in the intake.
btw I have been working on this problem for months and months so I have tried <u>all</u> of the usual stuff.
Thanks,Marty

cuatrokoop

Sounds like you are rich, not lean...

90/90Qs

I have no idea how engines run under low fuel pressure... I can't decide:
low pressure = lower power output = more throttle = poor fuel economy
or
low pressure = lean condition = higher fuel economy
thought someone might be able to tell me

FFFR

I believe i have the same problem....I put in BRAND new wires,distributer cap,rotor and plugs in my audi 90 20v and it still has a misfire! I checked the plugs and i one runs lean and tend to want to stall after i get off the gas and it returns to idle....I also have a loud buzzing fuel pump.......I have had many vw and not one this loud! possible low fuel pressure causes improper flow of injectors??