95 new yorker/Lhs is down - high idle

hello all...

My 95 new yorker is giving me fits. I have several cars and do my own work, this one is really getting to me. I signed on this forum, maybe someone out there in fix-it-land has a comment ?

Ok, it needed a tune up, 130k miles, so I did plugs,wires, etc and a new fuel
pressure reg. plenum came off, new fpr went in, got it all back together.

started it up and idle is high in park about 2000. When I put it in gear it drops to about 1300. runs good. will not drop to 800 rpm.

pulled IAC, cleaned. changed air filter, recheck all vac lines, tight
pulled EGR and found manifold feed tubes blocked. cleaned them,then blocked them off for a test, to see if egr was feeding manifold false air. nope.

Have checked all sensors and reset the computer fault codes.

Still get 2000 rpm in park, 1300 in any gear.

I didnt like the fuel rail gasket setup, cheap flimsy paper, yet I doubt I could be getting a vac leak like that from fuel rail. no fuel leaks.

All vac lines are tight,good rubber. FPR is right one, I have 39 psi on rail.

any thoughts ? thanks

steve

oh yeah, more stuff. The auto shit down relay did go off when I pulled IAC, etc. I knew bcuz I didnt get any fuel when starting. I reset computer and
verified voltage to sensors,etc. It all seems to work, and I have fuel.
I pulled IAC connected and it does move ok. So all has power as should.

only a high idle. throttle body closes as usual. I didnt adjust screw.

Brake booster vac line is tight.

Im either getting a bad pcm ???

or another way to reset PCM ???

or ???


thanks all

you either left a piece of the old plenum gasket on or did not replace it and it tore. has to be a vac leak spay some water or brake cleaner or 2+2 around to find out where the leak is.

Ok I had the same problem with my 95 LHS. I thought it was the gasket and had a friend spray some quick start around to check for leaks. None found. Funny thing tho was when he moved some wires to spray at the back the high revs stopped. There is a wiring harness under the black cover on top of the engine. Under here there is a wiring harness that runs along the top of the engine and down the back of it. I pulled and pushed on it and the revs went up and down. inally I got it at a place where it idles fine now. Don't ask why but its working.
Worht a look if your i doing the same thing.

thanks wayne and newfie 4ever.
It might have been a loose injector harness on your car wayne.

I pulled the plenum again and the gasket was tore, I bought a new set and new fuel rail ones too. they were all a mess. idle went down to about 1400,
then I capped of egr crap feed tubes and it dropped to 750. tubes were clogged by manifold.

It worked good 3 days, then I get hard starts again. I cleared it out, seemed flooded, worked 2-3 days again then same thing.

I pulled plugs and checked cylinders for coolant leak,head gasket, all of the chambers are dry.

Im getting new egr sunday. probably wont fix the of/on no start.
any thoughts ?

well,my 95 did that and it was the tps....hope this helps