That would be the throttle position sensor. We really need to make a list of these abreviations. I know there is one around somewhere.

 

Good idea HHDDB

 

That's not on the list. WHat is it? Looks like we need to add some.

https://ls1tech.com/acronyms.html

 

Grippy will fill you in in hhddb. He has been saying it for a while now, and I finally asked him WTF it means.

 

I just checked out the IAC motor on the top right of the TB, it is held in by the torx screws like you said and there are wires that plug into the right side of it, how do I check for carbon build up and would it be safe to spray carb cleaner in it?

 

i had the same problem as you. except there were times where my truck would completely stall out. i clean the idle air control valve and it works better now.

- disconnect the plug from the IAC
- take the 2 torx screws out (kind of tricky)
- pull out the IAC (but do not push the plastic black part in)
- i cleaned the black plastic part (pintle) with carb cleaner and a clean rag/toothbrush. do not immerse it in cleaning solution
- also clean part of the TB where the IAC came from
- then put the IAC back on, careful not to disturb the pintle

hope this helps

 

while youre there clean the whole t/b especially the idle compensation hole in the t.b blades. if that doesnt work, i think there a reprogram from gm about this. it may be elec. throttle only though.

 

Thanks, I was going to do it today but got busy, I will try this tommorow, how do you get the torx screws out without a torx set? What is the worst that can happen if I screw up? Also my truck dips to like 200 or 300 RPM when I put it in drive when it's having these problems. Hopefully this will fix it.

 

the rpms should drop when put in gear, but i am not sure how much. 300 sounds like a bit too much.

the best thing to do is remove the whole entire TB, therefore, it should make it easier to unscrew the IAC, plus you can clean the rest of the TB.

i didn't have the time to undo the TB so here is what i did. i had to use a 1/4" rachet with a deep socket, and in the end of the deep socket i put a torx bit. it was a PITA because i kept dropping screws into the engine bay somewhere. it would of been easier to remove the whole TB

 

Yeah I know it will drop a little bit but this is like 100 RPM's away from stalling it seems like.

Thanks for all your info.