Possible bad TPS??

[Eric08]

Hello all,

So I originally thought the truck could have a bad fuel pump but there are no problems at start up and it idles fine after starting up. When I am in neutral and rev the motor to about 2500 rpm it initially gets there, but then the rpm's start to taper back down while still holding the throttle constant. If you suddenly take your foot completely off the gas when doing this, the truck will stall out.

Could this be a bad TPS or IAC motor??

Or dirty throttle body??

Thank You

 

[BAILEY1]

Definitely sounds like the IAC is dirty and needs to be cleaned, or replaced all together. Try cleaning it first and see if that fixes the problem.

 

[Eric08]

Thank you I was planning to do that today. I will report back.

 

[Eric08]

Cleaned the iac and throttle body, but didn't fix the problem. I did find that the vacuum hose on the front of the TB was a little corroded though

 

[brink5]

Cleaning the IAC might not be enough. Seems that when they go bad, they go bad. No amount of cleaning will get them working again. If it were me, I would probably replace both the TPS and IAC. If you go on youtube, you can see how you can test them to see if they are bad to.