i have a 95 3.4L camaro and only on cold starts my car will idle really rough (the whole car vibrates quite a bit) and run rich. i was wondering if all of this could be because of my cat? according to my mechanic my cat is "shot" (i know the cat's done for, but i haven't asked him if this was the reason for the rough idle,etc..) I'm pretty sure it is considering i just installed a jasper engine 3k miles ago and it passed emissions with flying colors a few weeks after the install. Thanks for your help..

 

Does it idle fine once it's all warmed up? If so, might want to check your fuel pressure regulator and your injectors (you have to pull both of them to check either one anyway). If either one is leaking, it could cause what you're decribing, especially the FPR. I doubt it's your cat since it's just on cold starts. Your cat might be "shot," but IMO, it's unlikely that it's causing you the problems.

 

vibrations....might be weak motor mounts??

 

It idles alright when it warms up. Occassionally the rpms drop and raise a little when im idling after its warmed up..

 

Yeah, definitely check out the things i suggested... either of those would cause the symptoms you're describing.

 

ok, ill check it out. thanks alot