89 Iroc 5.0 TPI still has bad TPS symptoms even with new 99$ TPS...and still getting a code 22?

 

Are you just getting the code or is the car not running right. Did you test the TPS. Should be from .5V+- at closed throttle to .45 to .5V at 100% throttle.

Get the multimeter out:
Grey 5v ref
blue tps signal back to the ecm
black ground

Don't discount a bad TPS even if new...

 

No read out on my voltmeter with tps plugged in or unplugged of course with key on with old or even new one.

Ive cleaned aic sensor ....still in limp mode. And Ive read so many other causes possible...FED UP with this car!!😠

 

I know all about it ... Having said that if the ECM can't read the throttle position, it will run like crap. I took mine out last week and forgot to plug the TPS in after changing a thermostat. As soon as I touched the throttle, it fell on it's face. And, I'd worry more about how it's running than chasing codes.

So two things; trace that grey wire back as far as you can to see if you have 5V to it (Key On Engine Off). If you don't nothing else will matter until you fix that. Second make sure you're getting a probe in deep enough when testing ( Key On Engine Off). Multiple times I've had to rig a thin wire to get a reading.

I've cleaned, tested and replaced the IAC sensor a number of times. And it made no difference that I could feel. My car doesn't seem that sensitive to it so I'd look elsewhere.

 

Hey ...Im thinking exactly what you said ...it may be that theres no full connection between tps and ecm.. Is the ECM on the side of the front passenger foot area ?
you re encouraging txs !🙂

btw I m finally getting a reading using a speaker wire and putting ground on batt post. .Always a .4 v nomatter the position of the tpsHowever the reading changes from .3 to .8 if i use a diff ground!.Confusing!!

 

Reach up under the dash in the passenger footwell, just below the dashpad (sort of opposite where the heater box is) . If you're getting a reading like that and you're sure that you've got a good connection, then you have a bad TPS, even it's it new. The AC Delco ones are the best but to be honest they're all kind of hit and miss. Take it back and tell them it's junk.

Brian