Extremely slow throttle response

JHayes · 11-05-2009, 02:28 AM

I`m trying to help a friend with his step-son`s truck. It`s a 2002 2500 6 speed . Extremely slow throttle response when accelerating and decelerating. It sets p0122 and p0236 codes. p0122 will not erase.p0236 will erase 'and then come back when truck is cranked. Installed new map sensor. We`ve tried three pedal position sensors(two were new NAPA parts. Voltages are correct on map and APP sensors. APP has been reset a number of times. When accelerator is depressed quickly, no response until almost fully depressed. Very slow depression , acceleration is much better. After engine comes up to speed, RPMS don`t start to drop until accelerator is almost fully released. Does anyone have any suggestions?

dknoch · 11-19-2009, 01:43 PM

I don't have a good suggestion, but I am currently fighting the exact same issue. Good Luck! I will let you know what I find out if you promise to let me know if you come up with something. I am actually thinking a bad wire maybe.

Dan Knoch

GOTSOOT · 11-19-2009, 01:58 PM

go look up the 0236 code and see if it does not say something about your injection pump not comunicating with the ECM.

Mishkaya · 11-19-2009, 10:59 PM

P0236 (M) Map Sensor Too High Too Long Problem detected in turbocharger wastegate.
P0122 of course is the APPS.
It really sounds like an APPS problem, but if you have tried that, maybe that's not the case. I would highly suggest an APPS from Timbo though (geno's sells them I believe).
Another thought would be to check your grounds thoroughly. I always sounds corny, but you might be surprised to find out just how many issues are caused by bad grounds. I would suggest this thread as a good starting point:
Electrical grounding - finer points...
Good luck.