stalling/rough idle

[91Caprice9c1]

hey folks, im new here (posting at least) ive learned a lot by reading the threads for some time now. ive got the 5.7 in my 91 caprice.

anyhow, I am experiencing stalling at abrupt stops and an intermittent rough idle problem (fluctuating rpms between 500-1500). I recently removed, cleaned, and reset my IAC valve which did make a noticable difference, but the problem persists. I also ran some diagnostics on my TPS with a fluke meter and it checked out fine. i noticed that i have a somewhat damaged spark plug wire from laying on the exhaust manifold, could this have something to do with the weight of the problem?

i have a feeling i may need to replace my passenger side PCV valve (as ive already replaced the driver side). the passenger side PCV is lead into the tbi. could excessive crankcase pressure, or perhaps a clogged pcv be contributing to my problems via lack of vacuum passage?

also, i have very poor performance when traveling steep inclines, and the car suffers from a noticable drop in performance after warming up as opposed to when it's cold. Catalytic converter perhaps?

Thanks a bunch,
Matt

[CD Smalley]

Matt,

Sounds like your on the right track on everything to me. You might want to take that TBI unit off and check the gasket between it and the intake manifold. They have a history of failing and causing the hunting idle. Spray around it with carb cleaner to see if it steadies out first though.... Also, check your fuel pressure. My 89 would hunt for an idle when the fuel pump was weak...

[Gearhead406350]

I would change your plug wires i had the same problem and that fixed it, I have a 91 with a 305 same problem. But now it runs much better. So try that.

[91Caprice9c1]

Alright thanks a lot for the input.