Ok people, so after many months of frustration and pulling my hair out, I finally got to the bottom of my high idle problem.

Just to recap, my rig would idle at 1700 ish even after it was up to temperature. The only way to get it to idle normally was by physically closing the TB by hand or turning the engine off and restarting it. Sometimes if I blipped the throttle it would drop to 1000 rpm or so but climb right back up again after driving it again. I tried cleaning and testing my MAF, IAC, TPS and Throttle Body. Checked and double checked my vacuum lines. Lubed the TB linkage and rod, as well as researched until I was going cross-eyed but nothing would solve my high idle problem.

So what did I do you ask? Well I took the TB off again and really looked closely at the linkage and the throttle valve. What I noticed was that when I held it up to a light and looked directly at the clearance between the bore and the butterfly valve itself, as I let the valve close slowly, there was contact between the two surfaces just above the rod on the TPS side before the valve was completely closed and that contact spot would move up toward the middle of the TB wall as it closed all the way.



This caused the linkage to shift about 1/16" - 1/8" away from the TPS. Everytime I opened and closed the TB the rod would shift in and out because the throttle valve was hitting the wall of the bore and shifting out. I could actually feel resistance as the valve opened and closed while it was in contact with the inside of the bore. So I tried to physically restrict the rod from sliding back toward the TPS by holding it out and when I turned it, that way it closed completely all the way around the bore with no restriction whatsoever! So all I did to prevent the rod from sliding back was put a thin washer between the spring pack and the throttle body housing. IDLES PERFECTLY EVERY TIME NOW!!! Best of all it cost me nothing to fix it.



Try it out guys and maybe it will work for you!

Always awesome to hear about little fixes like this.
Props on figuring out the problem and fixing it.

wow well done, thanks for posting the pictures to explain this, glad to hear you nailed that problem

I have some weird idle issues myself. I'll look closer to my TB.

Pure genius man!!!

I've been having high idle issues and after inspecting my TB it looks like I am also having this problem. How do you take the TB apart so that you can put a washer in there to prevent the shifting? Thanks

The throttle body itself does not need to come apart, just the linkage needs to popped off. So in the bottom picture, disconnect the cables, remove the nut that's at the end of the rod and slide off the linkage. You may need to use a little force to get them to budge though but they will go.

Hey thanks Swede. I was having high idle problems too. It was a consistent high idle after driving that stuck around 2500 rpm. I cleaned the TB really well and sprayed inside the throttle cable housing to make sure that wasn't getting stuck either. Seems to have done the trick. Thanks for you thorough explainations and pictures.

When you rotate the throttle and see the shaft moving. Is the bearing inner race moving with the shaft or is the bearing seized or worn?

It be worth knowing what caused the failure even if a simple washer fixes the issue.

I'm wondering if this is the problem on my 97. She runs fine and drives fine, after driving a little while, idle starts to creep up to about 2000rpm. When I shut off the motor, and try to start back up, it takes a few cranks to get her started, then she feels like she wants to stall? Mechanic had mentioned something regarding low pressure in fuel pump? Any ideas?

now what is considered a high idle?,.... 2000 RPMS?....

and what is an excepted normal idle>? 1500???

did it stay high once you shifted into gear>?

High idle like 2000-2200. Happens after engine is warm.

Turned out to be...Coolant temp sensor...runs fine now..

Good advice. I was having an irregular fast idle problem for several months. After reading this post I looked for play in the throttle shaft and it was noticeable. The clincher was that when it was idling high yet fully warmed up, I could give the throttle shaft the lightest tug outward (toward front of vehicle) and the idle immediately returned to normal.

I initially pulled the entire throttle body to work on it, but later found that I could do it on the vehicle by just pulling the throttle linkage string. I also had to remove the dashpot (2 Phillips screws) to release its attached spring.

I discovered that a somewhat thin standard washer was way too thick and caused the linkage to bind. I thinned it by pounding it flat into a block of wood to hold it in place, then using a belt sander to reduce the thickness by 1/2. this appears to work.

Any chance of getting those pics back? I'd like to try this, and seeing pics before I get into the job always helps considerably.