Well...just changed my opti and my damn stumble is still there!!!! Plugs didnt seem to have any damage and the plugs are crap champions from guy i bought the car back from but none the less are fairly new. The miss is intermittent...it comes and goes at any RPM. It can come for a couple hours and then go away...but after i installed the opti today it just constantly did it when i got on it. Not sure what else could be wrong, correct me if i'm wrong but i dont think that it's mechanical if it comes and goes so other than that i'm not really sure, and ALSO IT NOW has some rattingling noise that i cant isolate to exactly where it's coming from, sounds like possibly water pump but not sure, didnt have this noise before install so now i have no clue, please help with some suggestions or ideas, thanks
Randy
email is stimpy5@hotmail.com

 

same exact thing with my car after installing the opti. if you come up with an answer, let me know too plz.

 

Dirty or clogged injectors
Low fuel pressure. Get a new filter, then check the pressure at the rails, it should be between 41 & 47, with the key ON but NOT running
Check the plugs, make sure they were gapped rite
Possibly bad ignition timing?
Bad wires, check them at night for arching.
Check everything in your emissions system too. EGR PCV ...

In a worst case scenerio, I think low compression could cause that, but thats like 99.999% chance of NOT being the problem. If you really pound your car though, maybe do a compression check.

The last thing it could possibly be would be like an vacuum leak either around the manifold or throttle body... Good luck guys