last summer i bought a tps senor from napa and set the volts to .60 . checked it this week and was at .39. when i went to set it back i only got it to go up to .52. what are some possible causes. how could i get it back to .60?

 

It was my impression that the TPS on the 90-92 TPIs are non-adjustable. As long as the voltage is below 1.0V at startup, there should be no problems.

 

As Vader states there isn't a need to adjust it (this is for the '90-'92 SD setups). However, since it is changing it may be caused by a sticky throttle body shaft or throttle cable. Something to check.

Al.

 

when u say their non adjustable does that mean the computer adjusts to what ever the tps is set at. because i had it set at .50 orginally and raised it to .60 and noticed and big difference in the sound of the engine. and my a/f guage was reading richer than before. my concern is that im running lean at wot. i dont even get a reading at idle.i know i might have a vacuum leak some where but should that effect a/f at wot.

 

Yes, the ECM keeps track of the lowest TPS reading and uses that as 0% TPS. Everything is based on the 0% TPS value.

Al.