My throttle cuts out, sometimes it works and sometimes it wont

[Bulldog88]

So I installed and 04 model motor in my truck, and I have the tac, pedal, and ecm from it, and sometimes the pedal will work and sometimes it won't, for example if I turn the truck on and I rev the motor up it will do it 2 -3 times then the pedal stops working, then if I shut it off and turn it back on it will work again sometimes depending on how long I let it sit. I even went to a salvage yard and got another pedal tac box and harness from a 04 and still nothing, I have not scanned it yet, I'm getting power at the tac box I check that out already so what can it be?

[BR3W CITY]

Can't tell you much until you scan it for codes. Mismatch errors may throw T or U codes so use a good scanner.

Depending what the scan says we can point the in right direction. Once the pedal detects a problem (bad pot/rheostat, shorted wire) it will disable the throttle control but still allow the ECM to command TPS for idle.

[Bulldog88]

So I scanned the truck and it gave me the tps sensor code , the readings on tps were not reading even, so I went to local salvage yard and picked up a complete throttle body and replaced it and it worked, now I have throttle response and my pedal works fine. Truck is up and running good