Help - 1993 FJ80 High Idle Issues (1 Viewer)

[GrawDaddy]

Hi all. I just purchased a 1993 Cruiser and there is a small issue with the idling. On start up it idles fine at 800-900 rpm. After the car warms up a bit the idle speed increases to 1500. Once the car is hot the idle goes all the way up to 2000-2200. Today I switched out the temp sensor hoping it was the failure but to no success. Are there any other thoughts out there? I have the repair manual and I am making my way through the checklist, but I thought I would throw this out to the pro's to see if anyone has any input.

Thanks!

 

[jonheld]

Have you checked the easy mechanical things first?
Make sure the throttle cable is not binding internally.
Make sure the throttle cable is not too tight. There should be slack and the throttle plate should be resting on the idle end stop when the pedal is released.

 

[Mighty690]

There is also an idle air control valve. You said "repair manual". Would that be the Toyota FSM?

 

[GrawDaddy]

Hey guys, thanks for the follow up. The throttle linkage all looks good, as well as the pedal. My next step was to attack the idle air control valve today. I believe that what I have is the FSM, it looks like this:

 

[GrawDaddy]

Btw here is the rig!

 

[GrawDaddy]

I just measured the resistance of the pins on the IAC, and found all within operating range (10-30ohm) except s2-s4, which is 40 ohms. Could this be an issue or does this seem small enough that the problem may be contained elsewhere?

 

[Dave 2000]

Air leak? Flexible rubber from filter box to manifold? Vac hose off or routed incorrectly?

regards

Dave

 

[GrawDaddy]

Solved. Went through and pulled all the old hoses, there were a couple that were cracked but it didn't fix the problem. I feel like a total noobie, but I had overlooked the cruise control linkage. It was too tight and for some reason kept pulling the throttle out slowly the more I drove the truck. So I gave it a bunch of slack and idle settled right down to 600-800. The cruise control may not work right with out a little tunning, but that's small potatoes! Thank everyone for the help.

 

[Shawn Spelman]

Have you checked the easy mechanical things first?
Make sure the throttle cable is not binding internally.
Make sure the throttle cable is not too tight. There should be slack and the throttle plate should be resting on the idle end stop when the pedal is released.

Thanks! My cable is too tight. Can't wait to loosen it up and see if it fixes my high idle issue.
Shawn