High Idle on 86 MJ Comanche?

[DrHeadlightNJ]

Hello I'm a Nube I know, but just got my first MJ and on start up it idles to 3K then drops down to about 1k, but when the engine warms up and I am at a stoplight the idle is high around 1500 to 2000. Changed all the vacuum lines, needed to anyway (original & dry rotted), changed the MAP (broke nipple pulling old vacuum line) I have read the post but it seems they post for 88 and up, I have an 86 2.5L XLS 4 cyl. any ideas? Thanks, BTW this is the best place on the net thanks to you guys I am really hooked now- line and sinker!

 

 

 

 

1986 XLS 2.5L

new floors this week, alleluyah

[lexluthier72]

Fuel injected, or Carburetor? IF fuel injected, clean the throttle body, especially the "flap" that opens to the airbox. IF carb, its time to rebuild the carb.

[jimoshel]

All '86 2.5 were TBI. All 2.8 were carburated. Either way, clean them.

[lexluthier72]

Thanks Jim! I just had this problem on a friends VW....same deal, cleaning the TB fixed the issue.

-E.

[JeffN]

the gaskte under the throttle plate may be sucked in

[dasbulliwagen]

The 2.5 TBI's have an electronic solenoid that pushes the throttle open when needed for AC operation or high power steering pressure. You might look at it to see if it is working properly and fully returning.

[DrHeadlightNJ]

thanks for the response gonna try it tomorrow also will look at IAC valve, but not sure what it looks like, :dunno: does anyone have pics of it?

[dasbulliwagen]

Its not so much and IAC as it is throttle positioner. It mounts next to the throttle body, and has a rod from it to the throttle arm to push on it. It is round, maybe the size of a "D" battery with a 2-3 inch rod coming out the middle to the throttle arm. Hope this helps.

[DrHeadlightNJ]

thanks dasbulliwagen, that is a big help, I was looking at it all the time and didn't realize it! ha will see tmrw. thanks again

[Thunderbear]

[DrHeadlightNJ]

Thanks Thunderbear great picture exactly what I needed