Not Running!
 

I'm needing a little help. I've not been driving my '91 much in the last year and a half and last October on a trip we stopped for lunch and when we came out the engine started fine but idled and maintained cruise power poorly. I replaced the coils over the winter and now under WOT it runs like a beast but still has major problems with smoothness at idle and cruise. There is a tech in town trained 20 years ago and he found a bad vacuum line but won't take it any further. I live in SE Oklahoma and am looking for someone competent on LT5's. Anyone out there have any ideas about a fix or someone that might be able to help it? Now that she's not running I really miss her!!

Re: Not Running!
 

I wonder how far jerry is from you. he's in edmond i think

Re: Not Running!
 

Any chance you popped the hose off the map sensor?

Re: Not Running!
 

Re: Not Running!
 

Stock injectors still? Any check engine light?

Re: Not Running!
 

If you were able to change coils yourself, then you already can do everything necessary to rule out vacuum leaks under the plenum. A mityvac or similar tool can be used to pull a vacuum on the various lines and fittings under the plenum, unless of course there's something obviously disconnected when you get in there.

If the cruise and/or HVAC aren't working 100% properly, then that would increase the likelihood of a vacuum leak being present.

I recently found a vacuum leak where the brake booster hose meets the plenum. It seemed snug, but after I put a hose clamp on it to snug it up, the idle smoothed out considerably.

Also, a failing throttle position sensor could do funny things at part throttle (not usually at idle, though).