I Bought it a few months ago from a old lady, She had it sit for a few months, and I have had it for a few weeks and it has been running Fine.
and this morning I go to start it and it normally idles at like 750. and it goes to idle at 750 jumps down to 0 back up to 1000 then down to 0 then Keeps going back n fourth like its gasping for air? ANY HELP please >.>



i cleaned out my throttle body and my air sensor. i also Used that guys method on checking vacuum leak and my jeep died.
I have a 1989 Jeep cherokee has a 6cyl 4.0

it has a eratic idle... it STILL jumps and drops i need help please.

 

What guy's method of checking for vacuum leaks?
Have you ever checked your intake manifold bolts to see if they've come loose?
Ever sprayed carb cleaner around the intake to find leaks?
Did you remove your throttle body to clean it and if you did, did you replace the gasket?
Have you got a voltmeter and are you capable of using it to check the TPS?

 

What is the TPS?

 

Answer all my other questions first and then I'll tell ya.

 

Probably a good douse of seafoam wouldn't hurt. But anyways, I had all kinds of funky things going on with my renix and changing the ignition coil helped a lot. Probably not your current issue, but you never know.

 

I am assuming when i figure out what it is.. it is just going to be a DUH kind of moment

 

It's not suppose to matter on that Renix, but I swear my on my 90 a few times when the idle was screwy disconnecting the battery for a minute cured it. Maybe the ECU bumps it up for the AC ? It's imposable, "black magic" or coincidence I guess. The only downside is reprogramming the radio. If it works for you that will make a total to two cases!

 

throttle position sensor, motor stalls when throttle body is covered that indicates no vacuum leaks,heres a link with testing procedure for renix applications you going to need a small meter for testing http://www.lunghd.com/Tech_Articles/...iagnostics.htm

 

So if there is no leaks would it be my TPS or air control sensor?

 

Maybe. Do you have a voltmeter and know how to use it? The TPS, like all sensors on a Renix, can be tested.

You're not llikely to find anything until you start diving in. The symptom you describe can be caused by more than one component or issue. You need to use a process of elimination to determine what it isn't, before you find what it is.

It could be caused by a bad ground connection between the firewall and the head and/or bad grounds at the dipstick tube stud. Peersonally, I'd start there since those connections are notoriously a problem and will cause issues sooner or later if not addressed.