I got this quote from another thread.

But if thats true...
My XJ idles EXTREMELY high.

When cold, it idles at 1k rpm, I thought this was normal Apparently not.
I knew when it warmed up, it had a high idle...usually idling at around 1500 rpm, and then after I have driven it, it will usually idle at anywhere from 1800-2000rpm in park or neutral. In drive it will idle at 1250 after driven and at a complete stop.

Am I correct, when I say, that I have a really bad vacuum leak somewhere???

 

Check your vaccums you are idling a little higher than normal.

 

Maybe check your TPS?

 

A good way to check for a leak would be to spray starter fluid around all of the intake joints/gaps/fittings before the engine gets too warm. When the idle stumbles then you have found your leak.

 

I idle at 800 rpms. sometimes 1000 on a weird xj day. just get it looked at by a good mechanic to get and opinin for free then we can help but it doesnt sound toooooooo bad

 

map sensor, with the jeep running unplug it it should stall then plug it back in and start it up, i had the same problem and that fixes it, once in awhile it does it but corrects it self automatically. Hope this helps

 

Hmm...maybe I didnt word it correctly or something.....

Im not trying to be a dick or anything....
But when an engine that has a 5K REV LIMIT IS IDLING AT 2K rpm, I would think something is WRONG!
Thats like my BMW idling at 3500 rpm, OBVIOUSLY something is WRONG!

I would like some ideas or solutions!
Not how bad you think it seems, or stating the obvious, that I have a high idle.


I also have positive crankcase pressure, which I was told is a bad thing... where it keeps popping the dipstick loose on its own. Though I doubt this is the reason for my high idle....

 

I'll try that, thanks.

 

Yeah...I usually use carb/choke cleaner, and have been trying this.
Problem is, I might have more than one vacuum leak, and with the engine running, you got pulleys, belts and fan blades to be weary of.

 

If you experienced the same probs....Then I REALLY hope this works!
THANKS!!
Will let you know!

 

Your belief is 100% correct, you're idling too high, I believe OE on an automatic is 700-750. I'm betting you have two separate issues.

1) One being sensor related. Could be a few different sensors, but I'd start with the TPS.. Be aware on an 89, it's adjustable.

2) Intake/exhaust manifold leak or one or more leaks in vacumn lines.

Also be aware: It's possible someone readjusted your idle set screw. Yes on an 89 you have one, well hidden but it's there adjusted with an allend wrench. . If true, this still wouldn't explain all of the behavior you outlined.

 

You can also pull out your IAC and try cleaning it.My 87 was doing the same thing,I ended up replaceing after I tryed cleaning it first.

 

Rent a vacuum presure tester (yes Autozone rent them) and check all your lines. Good luck!

 

Since there are few 'high idle' threads active, I posted a fairly extensive document under this thread.

https://www.cherokeeforum.com/f2/hig...99/#post389882

Hope this helps
Kent

 

Awesome write up XJ4Fun!
It looks like Im gonna have to wait for warmer weather though to do any of this. Unless I found access to a garage.
I dont feel like paying a mechanic when I can do this.

Also, Thank You to everyone who helped with an idea or solution.