puzzled...whats the problem?

I

Izzy

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May 11, 2008
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my truck for a long while now gets soft pedal off and on. sometimes i will have it for a few weeks and then out of the blue the pedal gets nice and solid. what it does is the pedal seems to escape from my foot, so i have to keep chasing the pedal to accelerate. it sucks. another example is if i have the smarty on, after each shift that my truck does while driving, it takes a while for the power to come on. i have singled out the vp44. i took it yesterday to a authorized bosch shop. he ran my pump through 2 different tests on his $240,000 machine. 4 hrs later, he gives me my pump back and says there is nothing wrong. ANYBODY HAVE ANY IDEAS WHAT TO LOOK FOR NEXT???
 
No offense to the company that ran the tests, but their $240,000 machine can't replicate the under hood temps or conditions your pump experiences when you drive down the road. You may still have a VP problem.

That said, I'm putting my money on the APPS. Those are pretty classic examples of a troubled APPS, and since the VP was tested, I would put my money on that. You can get a complete replacement from Cummins, or there are a couple of upgrade options out there too.
 
now i know that u can buy just the apps and put it on yourself, but i am not good with adjusting electrical voltages and whatever else needs to be done to install the apps. so i guess i will probably buy the whole tps and give that a shot. where is a good source to buy a tps?
 
Does the pedal move all by itself? I don't get the "chasing to pedal" bit. If the pedal is moving by itself, it almost sounds like the vacuum system is somehow engaging the cruise control and causing it to move the pedal by itself.
 
Big Blue24 said:
I don't get the "chasing to pedal" bit.
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yeah, i dont blame you. that was kind of a bad explanation. no, it does not run away. what i was trying to say was it lacks the power for the position my foot is at so i have to keep pushing down just to drive normal. i understand that a pedal has to be pushed for the truck to move but what i am trying to explain is the amount that i have to push is not the normal amount for the amount of acceleration am getting in return. i hate it.
 
See if you can find a friend that is willing to swap them long enough for you to check them.

The full assembly isn't cheap.. It would be nice to know for certain that is the issue before you drop that much coin on it.

From everything I've heard, the Timbs APPS is the route to go.. I don't have any information (contact or otherwise) with me here though. Sorry.
 
It sounds like the electronics on your pump is going bad,you can go to bluechip diesel website and it will explain the process to check all your problems with your throttle. Good website
 
If you can get some one with a scanner to hook up to your truck watch the apps % and voltage while moving the pedal slowly up and down truck doesn;t need to be running. If you don;t see any thing odd like voltage jumping around or % changing wierd, drive it and watch it again. My bet would also be the apps is bad.


IKE
 
Or a multimeter at the apps harness or pcm works too. There's directions on this page in the dodge tech section.
 
IKNOWEVERYTHING said:
If you can get some one with a scanner to hook up to your truck watch the apps % and voltage while moving the pedal slowly up and down truck doesn;t need to be running. If you don;t see any thing odd like voltage jumping around or % changing wierd, drive it and watch it again. My bet would also be the apps is bad.


IKE
Click to expand...

tried it today. hooked up a scanner to it. at idle the volts were 0.35. at wot the volts were at 3.52. when accelerating the pedal and decelerating the pedal, the voltage would instantly change at a slight movement of pedal. the change in voltage was very responsive to the movement on the pedal.
 
i did these tests with both the truck running and not running. same reads both ways.
 
swapped my friends tps into my truck...problem solved! pedal is stiffer than ever. truck runs like the first day i bought it.
 
Izzy said:
swapped my friends tps into my truck...problem solved! pedal is stiffer than ever. truck runs like the first day i bought it.
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Great news!! Glad it worked out for you!! It's always nice to sole a problem and move on down the road.
 
u can say that again...when u get ur truck to run like its suppose to, u become a very happy man.
 
well, i installed a brand new apps(timbo aka williams apps) on my truck. i still have the delayed reaction of acceleration. the only difference now is it comes and goes. i left my friends house and the pedal felt like with the old apps, then it suddenly got stiff and the acceleration was dead on with any movement of the pedal. no delayed reaction at all. woke up this morning, took the truck out for a drive and the pedal was back to delayed reaction again. later on today the pedal sensitivity got good again. :bang this is very very annoying. it drives me nuts. the part that drives me nuts the most is when i think that maybe its just me then all of a sudden the pedal becomes solid and rapid response.

another example: when the pedal is at its best, it does not take more than 1/4 movement of pedal to get all the power i need. when the pedal is at its worst, it takes 3/4 throttle.

what is next? what do i try next? a whole new tps assembly from the stealership?
 
Check all your connections at the PCM and right at the APPS. use some electrical contact cleaner and some dielectric grease to seal things up. Sounds like a bad connection if you ask me.
 
I have a complete good working APPS off my 2001 I will sell you for $100 shipped. I put a P-pump on my truck and no longer need it.
 
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