735 IL Engine miss

[bweera]

My 1990 BMW 735 IL, has a terrible engine miss. It happens during slow or fast driving. Once in a while it will run smooth. I have replaced the fuel filter, O2 sensor, spark plugs and have added various gasoline additives. No results.
Is there a PCV valve in this car? I would be grateful if someone could tell me what I need to check and replace before I go to the dealership.

[jarhed]

Hey,

I'm not a BMW pro or anything (only on my fourth one), but every time I've had that issue, starting with my old 320i, my 318i, and now my 735iL, it's usually come down to a loose or old vacuum line.

As a general rule, when I buy a bimmer, I replace all of the hoses I can. It's cheap enough and easy enough for me to do myself.

Just my .02

PS: STAY AWAY FROM THE DEALER!!! Unless of course, you are independently wealthy and can afford to pay three times the going rate for repairs. I've found several smaller BMW/Mercedes service centers who are trained and do a wonderful job.

[donriko]

Originally Posted by bweera

My 1990 BMW 735 IL, has a terrible engine miss. It happens during slow or fast driving. Once in a while it will run smooth. I have replaced the fuel filter, O2 sensor, spark plugs and have added various gasoline additives. No results.
Is there a PCV valve in this car? I would be grateful if someone could tell me what I need to check and replace before I go to the dealership.

easy fix you need a throtle position switch i did had same problem fixed. its ontop of engine by the air intake