My brother has a 2002 2500 CTD automatic with about 116K miles. He has had some dead pedal symptoms and had the throttle position sensor (APPS) replaced mid October, which fixed it for a while, but it's recently started doing it again. The mechanic that replaced the sensor said the VP44 had already been replaced at some point, so I would hope that it is not causing a problem. Any suggestions on what else to look at to solve this issue? Has anyone experienced this problem even after replacing the pump and APPS?

 

make sure the lift pump is working properly first before going any farther.

 

My 06' was doing the same. It took three weeks of trouble shooting a sensor here and there only for them to find a short in the harness from the computer to the pedal. One of the give aways..I was pulling my toy hauler when it occured. I was able to get the truck speed up enough to enguage the cruise control..Once I did..the truck excel'd just fine using the steering wheel controls. Come to find out the "pedal" circuit has to distinct paths. One for the cruise, andone for the pedal. This enabled them to trouble shoot the pedal and find the intermitant wire problem. Good luck!!

 

when you say dead pedal, what do you mean ? i put a post up a few weeks ago, saying that if im driving, engine hot or cold...say im cruisin down the highway and im at 1800rpm at 65-70 mph all of a sudden ill keep the pedal at the same position and or put it to the floor and it will stay at the same rpm and start slowing down, like its not getting more fuel when i push the pedal. pushing the pedal will not change anything, and all of a sudden it will kick back in and dump the fuel in i want and go. i dont know what the hell its doin. i have the juice with attitude, and i watch the gauges and it wont boost over 5-6 psi and my fuel psi is at approx 8-9...WTF! so maybe im experiencing the same problem

 

Drew, Hikeyd, thanks for the input. I'd forgotten that the lift pump could be the culprit. 02Cummins, I don't have any performance mods or guages, but I am experiencing the exact same problem you described in your post. It is very unnerving, especially when pulling out onto a busy highway. And you never know when it will happen. Even with cruise control on, it will lose rpms and mph until it "catches" and dumps the fuel and downshifts in a roar. I am considering BD's OEM bypass lift pump. Have any of you guys had/heard experiences with this one? I am almost afraid of simply replacing the stock lift pump with the same thing. Thanks.

 

Check the sensor again. Just because it is new, doesn't mean it is good. This happened to a buddy of mine while we were driving through the desert in NM. He spent over $3000 trying to fix it (repalced ECM,sensors and other stuff) and it turned out his brand new TPS was bad.

 

yea i was thinking it could be th elift pump causing this problem, but im not sure, i cant see why it would be so intermittant...i dont know what to do, im changin the lift pump soon anyways to an after market probly fass or something, gotta read up on it, just wish i knew exactly what it was

 

guys, from what I have seen and read on here, if you experience a throttle malfuction while at highway velocity , then you may have :

bad lift pump

bad fi pump

dirty fuel filter(s)

faulty sensor

shorted wire harness

or you may just be driving a FERD!

 

We had to unhook the battery for about 15 minutes each time the throttle went dead. It was a pain, but it got us out of white sands.