MFEUSAF

so i was driving down the road. i would say about 70 mph, and i was coming up on a car, so i let off the foot alittle and when i went to accelerate again there was no power at all.. and the truck just started to decelerate. i could tell it was giving it fuel but it just wasent making power.. so i dropped the stick in 4th gear, and tryed to accelerate again, it bogged down alittle then the power kicked back in. and it was fine.. shifted back into 5th.. good to go. it was the wierdest thing ever. and i cant get it to duplicate. the only time it really dose it is when im going over 65-70 mph and i let of the accelerator to slow down alittle then try to accelerate again. up hill, down hill, flat road. same thing. no performance chip turned on, no propane, nothing. full tank. i dont get it. i can put the foot to the ground and no power.. im stumped. Any suggestions?

jrs_dodge_diesel

One of two things that I can think of.

1 is the APPS (accelerator pedal position sensor) has some dead spots and it needs to be cleaned, adjusted and reset.

2. Your VP44 (injection pump) is dying. See if you can get the codes pulled. One way to confirm the VP44 is the code P0216 - injection pump timing failure.

Hope its just the APPS as the VP44 is much more involved and expensive.

crobtex

Try this: https://www.dieseltruckresource.com/...n&onlynewfaq=1

It's a pretty common problem and this may help. If the problem presists, you will have to replace the APPS. About $330 from Cummins (not Dodge dealer) and about 20 minutes.

THANKS FOR SERVING!

MFEUSAF

so the APPS is the one connected to the throttle cable above the pump?

crobtex

Correct. It's under the black cover.

I had to keep resetting mine every now and then for a few months, and finally just replaced it.

MFEUSAF

i wonder why it only dose it at speeds over 70 mph and why it fixes its self when i downshift. thas just odd.

crobtex

In the end mine would do it at any speed , but mostly at highway speeds. I don't know why they regain their composure, but they do.

There is a thread on here somewhere telling how some folks done the re-cal themselves. But, I think some screwed up their ECM trying to do the re-cal.

MFEUSAF

im an aircraft engine mechanic in the USAF, and i can totally understand how some parts just have grimlins in them. but this had me stumped. i guess i can try and reset it and give it a whirl. if not i'll be back to the whole "switch parts till it fixes itself" method.

crobtex

Have you checked to see if you have any codes? The APPS will usually set a code from P0120 to P0124. I think P0121 is them most common.

MFEUSAF

no i havent, do you just go to a dealer or what, i hate going to a dealer for anything. plus right now im in kuwait. makes it kinda hard to drive her over there.

crobtex

I think you may have a problem. There's probably not too many Auto Zone stores over there.

Seriously, most all major parts stores have code readers and will read them for free.

MFEUSAF

alrighty, when i get back ill have it hooked up before pullin the engine.. 53 block strikes again.

crobtex

OUCH! I hate to hear that!

MFEUSAF

i have pulled the engine before to weld it.. no luck. cracked again. so now im goina just get a short block. gotta find one first. dont even know where to begin to look. and never pulled a diesel apart.. shouldnt be much harder than a rolls royce T-56 Turbo Prop engine.. haha

crobtex

I've never rebuilt a Cummins, but I wouldn't think there would be much comparision.

Good luck and take care of yourself.