I had a scanner on my car the other day, and other than running rather rich, the only thing I noticed that didn't seem right was that my TPS read 5% at idle. Is that what it's suppose to be, or should it be 0%? The car has a holley 58mm tb on it btw....

Just trying to figure out if I need to slot my TPS or not

Thanks

 

Throttle position percent is figured by the PCM based on the closed throttle TPS voltage. What is the TPS voltage showing when the TPP shows 5%?

Some OBD-II hardware scanners appear to show a positive number for TPP at idle.... but the software scanners show the correct 0%.

 

I'm not sure I didn't look at the voltage. I'll put the scanner back on it this afternoon and report back...

Sorry, I'm a noob when comes to figuring out the tune on these things

 

I believe the PCM will also store its scale of the TPS % vs. TPS voltage. I found on my Impala SS that if I increased the TPS voltage by adjusting the TPS, it would go from 0% to 1%, but I'd still be below .95v. If I disconnect the battery, reconnect it, the PCM would "reset" its calibration of the TPS to 0%.

I also had to slot my TPS for my BBK 58mm throttle body.

 

Ok, finally got a scanner back on it. TPS voltage at idle was .76v and now reads 0% (somehow my tps was not seated all the way on my tb)

But i figured out what my drivablity problem was too....my left o2 was sticking on a lean reading, so my injector pulse was waaay up on left bank. No wonder it was being sluggish and puffing black smoke occasionally

 

Awesome!