Daily driving 1991 Camaro z28 with about 197,000 miles 305/700r4. Was able to get my hands on a Tech 2 scanner from GM and recently had Check Engine light come on and then car wanted to stall barely and then it did and fired it back up and drove it more and acceleration made it go away. Any experience with these codes and would one be causing the other two to also appear?

 

What’s tps voltage at idle ? Any glitches in voltage when the throttle is depressed?

 

Hey there, i got myself a fluke 88v recently , so what range should i be looking for?

 

Backprobe the blue wire at the tps. It might be non adjustable but should be .67-.75 idle and increase when throttle opens wot 4.5v. Grey wire to tps is a 5v reference.

 

okay ill get right on it and bring my results

 

so here were my results i took pics since it was my first time using my dmm





reference 5v wire


idle throttle

idle throttle

wide open throttle

wide open throttle

 

Are you checking the tps ground ?

 

oh darn, i didnt check it. ill go check it right now. what reading should i get? im a noob 🤣

 

when i checked the idle by directly putting the leads on the ground and the signal wire , i got 0.59 at idle and 4.45 at wot, compared to the 0.61 idle and 4.44 connecting the ground lead to frame of car. Did i measure the ground wire correctly?

 

Yes you measured correctly. Might clear the codes and see if 22 comes back.
just remembered tps ground shared with mat so I don’t think it’s a ground issue might effect both sensors.
might try this trouble tree

 

okay so i should delete those other codes and see if any reappear? and go from there then

 

What is the ALDL?

 

It’s the connector under the dash drivers side knee level.