High Idle

[KSjeepguy88]

On my 88 MJ 4.0l, my idle is very high and I can't find out why...

 

I've cleaned the Throttle body and IACV, replaced some vacuum lines and adjusted the TPS...

 

I don't know what else to do to see if I can get the idle lower, but to replace the IACV.

 

Thanks for the input

[AeroNautical]

This topic has a wealth of knowledge on how to solve that problem: http://comancheclub.com/topic/38612-very-high-idle/

 

Hope it helps, and good luck. 

[cruiser54]

On my 88 MJ 4.0l, my idle is very high and I can't find out why... I've cleaned the Throttle body and IACV, replaced some vacuum lines and adjusted the TPS... I don't know what else to do to see if I can get the idle lower, but to replace the IACV. Thanks for the input

Do the sensor ground test-16th post

C101 refresh-14th post

Connector refreshing-7th post

Ground refreshing-13th post

 

in my link below. 

 

Get that stuff behind you before monkeying around changing parts.

 

How did you adjust the TPS? 

Has it done this for a while or is it new? 

[mjbret13]

I am having the same exact problem with my 88 also. So far I have replaced the iac and adjusted the TPS per cruisers instructions.

[cruiser54]

I am having the same exact problem with my 88 also. So far I have replaced the iac and adjusted the TPS per cruisers instructions.

Do the stuff suggested in post 3 before dinking around replacing expensive parts. Takes an hour if you're real slow. Costs nothing..............