Im trying to run down an electrical issue in my fuel system (L99)

Every so often when I go to take off, my pedal will just dye. No response for about a half inch. If I mash it then it will pick back up. Its not every time, and I cant figure out a common denominator when it does happen other then using the pedal. . . Itll dive from 2k on the tach to 1500 and just keep bouncing between there. First gear is the worst, it hasnt really done it in fourth yet. I think Ive checked all mechanical stuff, wiring harnesses, oil lines. Im not leaking any oil from anywhere, I forgot to mention my fuel pressure doesnt move at all when it happens.

Ive got a TPS on the way just in case thats what it is figured Id check in and make sure im not missing anything.

I guess its technically a pedal position sensor? Trying to get torque logs figured out

 

Sounds to me like you are on the right track

 

Look for the thread by Robin, aka PaysonPSD. It has lots of pics and help.

Stewart

 

You need the proper tool.
Torque Pro will let you see the TPS in real time.
It only updates at about once per sec. but that should be workable.
You can just watch it and cycle the pedal until you are sure that its good or bad.

 

Cut out the middle-man and backprobe the connector and use a VOM.

These are basic Potentiometers that inhibit voltage to the PCM by way of resistance (5 vRef pull-down circuits). Scantools often miss the event all together. A better tool is a Lab-Scope or Graphing Meter if you have access to one.

 

Welp I got bored and skipped all the proper diagnosing and replaced it no more problems lol