I have a 1988 Jeep Cherokee and have a high idle problem. I will start up on high idle and not come down from it. Could anyone please tell me the problem. We have changed the O2 senser. That did nothing for it. Please help!!!!!!

 

.Check the IAC.

 

check your filter and it may be time for a tune up .

 

We have checked the IAC, problem still there.

 

I had the problem of fast idling on my 89 laredo, tried slapping the fuel pedal did nothing, follow the linkage from the pedal thur the firewall to the above center on top of the motor the (accelerator cable) where u are able to move this linkage forward and backwards to speed the motor up and down (also theres the return spring) which may be old and rusty which will stick. here put some either release-all or wd30, ..also their is a little black rubber thingie behind this with 2 holes in it where one u have some line coming to it make sure this is properly seated in place.. mine used to fall out sometimes and gave me a pain many times trying to figure out what was wrong..also check ur vacuum hoses, the shape they are in a loose one or cracked one will cause u this problem too.

 

EGR valve.. block the sucker open and see if this solves your issue!

 

Well thanks for all your replies, but problem still with us. I have changed the MAP senser and that is not it. Still looking for help!!!

 

maybe the MAF , could be so dirty its not able to close properly

 

Sounds like a sticky throttle line. Make sure that the throttle bar goes all the way down after letting go of the throttle. You could adjust the throttle line. Is the idle always high or intermittent? Is this a new problem or has been around since purchase?