It takes a bit to start and then idles like crazy in park. But as soon as I put it in gear it smooths out to normal. The inside of the intake manifold is pretty dirty from the blow-by, but that is fixed now. It has been doing it since I got home. And there is no problems that I have noticed while driving. It just happens in park.

 

Probably the same in Neutral, when there is no load on the engine.

I'd pull the throttle body and give it a good cleaning. A new base gasket is like $2.50, a can of carb cleaner is $4, and a cheap toothbrush can go a long way. Specifically, get the ICV ports cleaned out. If it's sticking open a little, you'll have a high idle. If it's sticking closed, you'll have hard starts.

Did wonders for the starting/idle on mine.

 

does an 87 cherokee have a throttle position sensor?my 89 f150 did the exact same thing and it was the tps

 

Ah, crap, it's an '87. Didn't even see that. I dunno.

 

Yes it is a Renix and has a TPS and an IAC also called the Idle stepper motor. I would bet the IAC has never been off to be cleaned. If you take it off(T-10 torx) be very gentle with the idle pintle. That is easily damaged. If cleaning the IAC does not improve your idle then post back up and we can then try some more complicated fixes.

 

Just as a note, when I cleaned the IAC on my '93, just cleaning the plunger didn't help. I had to remove the entire throttle body and clean the chamber out, it was full of a tar-like substance.

 

That happens when a Jeep sits for an extended period of time and seafoam can usually clean it without disassembly. Sry you had to take your apart.

Hope it runs well now Code.

 

Runs great, thanks!

Wasn't a big issue, unhook two electrical connections, unscrew like 8 torx bolts, and a new gasket.

 

They have a tendancy to leak at the gasket surface and will often run worse than before the cleaning. That's why I always suggest the Seafoam to keep from breaking the gasket seals. You either were very diligent in cleaning the two surfaces or you got lucky. Either way I'm glad it is running well now.

 

typically,i believe, a bad idle air control,much like a bad egr valve will cause stalling at idle

 

If the pintle sticks it can cause either. It depends on if it sticks in or out. That sounded bad but you understand if you have had one apart to clean it.

 

When I bought it I checked the air filter first to see how bad the blow-by was, and it had a bit of oil in it. So now that line just goes into a cut-up bottle by the air intake. I pulled the throttle body off and cleaned it out and the IAC. But there is still a buttload of tar in the intake manifold. I want to seafoam in but it would be hard to do on post with the reported white cloud that comes out. But also I didn't replace the gasket to the throttle body. I know my fault. So do you think it might be cause the gasket is pretty much crap. And I also snagged a multi meter today to take care of the TPS.

 

If the gasket is leaking, it's going to run funky. Autozone has them for like $2.50.

 

My 2008 hemi does this hi idle every time it is started . Dirty TB ?

 

Replace the gasket. PM me your email address and I'll send you a simple tutorial on how to check and adjust your TPS with a voltmeter.

Anyone else want it, do the same.