Throttle Body Won't Close
 

I have a high idle issue that i get if i gently let off the accelerator,

if i quickly let off the accelerator the TB will snap closed and idle fine.

If i manualy press down on the TB accelerator linkage it will close another 1/8th inch and idle just fine. I have compleately removed the dashpot and it does not seem to make any diffrence.

This TB has been compleatly removed and cleaned about 2 months ago when i did a new engine install. It is squeaky clean inside and never did this before, only after i got everything put back together.

If the engine is not running it opens and closes smooth as silk, when the engine is running something is stopping it from closing that last 1/8 inch.

Help, what did I do to it?

Cable binding?

Subscribing to this thread....I had this same issue after my rebuild, and I'm not sure how I fixed it :laugh::dunno: but the last thing I did was adjust my TPS. I messed with so many things at the same time I'm hoping someone knows exactly what to do so I'll know in the future.

My thought would be to take the throttle body off and look for some kind of mechanical binding. I can't imagine your engine creating enough vacuum to hold it open.

I have the same issue every now and then... my dad decided to "spray some.........into the throttle body to clean it, and after that it wanted to idle at whatever you revved it up to. The RPMs would never drop. Eventually it wore off (I think, or he may have done something else to it) but every once in a while I'll notice a higher idle. if I rev the engine and let my foot slide off the side of the pedal, allowing the pedal to snap back, it returns to normal. I also notice a shot of WD40 on the throttle cable and all the linkages helps too.

Man i wish i had a better reply...

It has gotten much better, seems to close better every day now it only holds it about a hundred or so RPM's above idle (750).

All i can think is that i completely cleaned every inch of the TB and maybe some of the linkages needed some lube. I lubed up the big spring on the left side and some other parts with silicone spray and it helped LOTS. At this point the sticky throttle should be gone in about another month