Alright guys, i have a 92 z28 l98, and three days ago I reset the TPS voltage since the car was running like crap (surging and stalling). Today, at a stoplight, the car acted up again, it started to surge etc; went to go check on the voltage; it was off again. So i reset it again... Im just wondering what could have caused the TPS to go off like that?

Also, the car idles at like 950 in park, and 750 in gear; is this correct? I know where the IAC minimum air adjustment screw is, but there is no way that I know of that i can turn the screw, it has no hole for torque bits or screwdrivers, its just like a screw without a head... The article said that I needed a "punch" or something to allow for me to adjust the idle; what exactly is a "punch"? Also, how would I go about adjusting the IAC too?

One more question- is it an absolute neccesity to reset the ECM after TPS adjustment? What are the ramifications of not doing so?

I apologize for my ignorance in advance.

 

First thing is make sure the bolts that hold the TPS in place are tight, not torqued on but snug enough that there is no way that you can move them with your fingers, if the engine vibrations are moving the sensor that might explain your TPS voltage changes.

As far as the "punch" it could also be called a "pick" or basically any tool that helps you remove the plastic piece that is usually covering the torx head screw that is in place. I would make sure to do the IAC Adjustment before you set the TPS, remembering moving the idle screw is going to change your TPS setting, so do the the IAC min air adjustment first and then set your TPS. Also make sure to set the TPS using the pedal from inside the car, not by pulling the throttle linkage all the way forward with your hand. You are able to pull the throttle linkage forward much farther with your hand then you can with your pedal, meaning that you might not actually hit WOT with the pedal - you might want to use a pedal buddy to help you get it right

 

Why would you wanna go WOT while setting the TPS? I was under the impression you only moved it to WOT to check to see if the voltage was over 4.0. I did these two things the other day and it made a workd of difference. I check mine regularly.

Will

 

WOT voltage is anything over 4.25

Therefore you want to check both idle and WOT like you said, just because the voltage is correct or in the limits for idle does not mean the voltage will be correct for WOT.