I have a 1991 Pickup 4x4 with a 3VZ. After my engine has warmed up I am noticing that my idle when I come to a stop stays around the 1500-1700 range. I have checked and reset my TPS, Checked and replaced almost all of the Vacuum Hoses, checked and cleaned my dashpot. Checked and tested my egr. I am NOT getting any CEL codes but my truck will not idle. Any ideas? I am totaly frustrated... Oh, also, fuel economy seems down. Help Please!

 

mine does that also. I am hoping that I do not have to replace the IAC (Idle Air Controller) because those are expensive.

 

Have you tried adjusting your ignition timing before buying parts?

 

agree with maco, and was just about to say the same thing....try adjusting you ignition timing, if its advanced too much, it can do that...maybe the bolt that holds the dist in place backed out or something...who knows.

 

Also, I have changed the whole throttle body out with no luck. I really doubt my issue is related to IAC. I checked that coolant is getting into it. I am wondering if it is failing to get out of the Cold Start loop. What or how do I check this? What is odd is that I can pop or quickly press & release the throttle to get it to idle down. Occasionally it does idle down to low? I have spent numerous hours going over the throttle body. There is one other odd thing it does, occasionally the truck seems to hesitate or stall (Lasts just a second), this generally happens when the throttle is constant and has never happened under load usually when cruising on freeway, it jolts the whole vehicle. Thoughts?

 

I have not had timing checked, although the Dist is tight and has not moved since the engine ran correctly..