my 89 cherokee revs up to 3 grand when i start it and when i put it in gear cuz of the load it goes down to about 15oorpm but wont idle any lower? my EGR is bad but im not sure if that is what is causing this.

 

Check your t.p.s,if it has moved or not working properly it will cause this,it can also cause the trany to not shift properly,the egr will cause it to run bad,not sure about raising the idle up. I assume you checked the throttle cable.

 

You havent filled in what engine you have under your profile so Im going to assume you have the 4.0 I6. You should take the time to fill that in so that anyone who is trying to help will know the basics of your rig..


Clean the throttle body with a Sensor safe throttle body cleaner/carb cleaner. Your going to want to remove it from the intake to do that. If it is really gunked up use kerosene and brush the throttle body with it after you remove the tps and the Iac(Idle air control) . Check the IAC pintle seat on the trottle body and make sure it is clean. Do not use anything that will damge the seat like a screwdriver. use a plastic knife or something similar to remove the crud. Check the Iac and clean that so the pintle will move freely. The TPS is adjustable on your jeep( Im assuming you have the 4.0) so after you clean the throttle body you will have to adjust the TPS again. its really simple to do. Heres the link to a thread that describes the procedure for it.. https://www.cherokeeforum.com/f2/hesitation-misfire-help-19233/. once you get that far start it up and see what its doing... then get back to us.

Check for any vacuum leaks. this will also cause a high Idle.

There has been a ton of threads about this . Take a few minutes and read up . Usually you will find what your looking for.

 

It's the idle stepper motor on the TB, unscrew it, pull out the stuck piston rotating it with some pliers, spray some wd40 or equal, put it back on, test, if it stays stuck another tme repeat operation and unplug wire until u get a new one.

 

And do also all the things that bishop letov said.

 

Thank you all very much. It looks like i have alot of work ahead of me today. I will get back to you as soon as i get it all done i hope it works i dont want to have to sell my baby.

 

so i did a little cleaning and i checked all my hoses and everything is plugged in i check my IAC and the plunger was stuck so i tryed lubing it up and getting it free and well it didnt work so i got a new one and it seemed to help a little it revs up when i start it but now it drops down to regualr idle i guess its better then nothing but if you could think of any other reason it could do that maybe the CPS sensor?

 

It is supposed to rev up at cold starts, it is normal. The CPS is ok.