"dead pedal"/ odd shifting........

[geonc]

on a buds '96 PSD.
Someone has him convinced his TPS/pedal assy is shot and wants to replace it .....about $300 or so from the stealership

Truck idles fine but when in gear driving nermal, has a "flat spot" and shifts wierd and fast

Not being familiar with these autos....any thoughts where I can help him out

Truck seems to have good eng speed control in park so I believe the pedal assy can be ruled out and these wierd actions happen regardless of O/D in or out and speed-o-meter is working fine.

Tranny fluid is clean and full but I haven't pulled the sol pacs yet, nor have I messed with what I relate to the FIPL switch on the pre PSD {not that I would know whut to do with it if it bit me }

 

[Doggy Daddy]

The failure that I have seen is that when you press the accelerator the engine remains at idle. The pedal assembly has 2 parts; the Idle Validation Switch that is just on or off to tell the PCM that you are not pressing the pedal (this is the portion that I have seen fail), and the sensor portion that tells the PCM how much you are pressing the pedal. I have not seen the sensor portion fail but it is possible.

Sounds like it needs some diagnosis; are there any codes?

 

[geonc]

for theonly reply ...dang guys lotsa views but not even a sarcastic reply {regarding my "bolt action"affliction }....do I smell?

No codes showing
Does the PCM respond to the speed sensor as far as eng fueling while the tranny is in gear?

 

[Double-S-Diesel]

try driving using cruise control, this takes the pedal out of the system.
I have had cps s do the same type of thing.
worst case take a known good pedal and try.\
also could put on graphing scaner or lab scope and look for the glitch.