1995 Riviera shakes, rattles, but no roll

cabbb19 · SE

Hello,

I am trying to fix a 95 Riviera with a supercharged 3.8. The car runs fine when It is hot but when its started cold in the morning, it bucks and shakes and stalls. It will not keep an idle when cold. I have to get it past 2 grand and let it idle there for a while before letting it down to 800 rpm. I have replaced many items on the engine and it is running better but still gives me problems. I think I detect a small miss on occasion. The items I have replaced are as follows: EGR, MAS, ECM,coil packs, plugs,fuel pump, fuel filter,all vacuum hoses. I got these items cheap from a junk yard and I know they work as they were tested before the engine was seized for the cash for clunkers program. I really am getting frustrated with it and want it out of the driveway. My labor is free because its an inlaws car. Help

brad360 · GT

there are several other sensors that could cause that, The o2 sensor on the manifold,MAP, a Plugged EGR (most likley the culprit), i would take the egr valve off, and spray the pintle with some PB Blaster, or WD-40, while moving the pintle gently with something small. And re-nstall, might need some gasket goo to re-install.

asia · SE

you may consider the camshaft sensor... or possibly the crankshaft sensor although the latter generally will prevent the car from starting.

Could also be a vacuum leak that lessens as the engine warms up.

streetracer · Site Admin

Most of those options are what you should be looking at.

I just know that back in 95 with the supercharged 3800 they are a bit different and picky.

I would start with some starting fluid and spray around some of the vacum lines and see if your idle goes up. If you dont find anything like that then pull your EGR