I have a 2004.5 cummins with 123,000 miles on it. When i have the truck in tow/haul mode and get the RPM's over about 2,000 or more the thottle will like stick right around 2,000 RPM's and will not go down. This just happend recently and i have been having to switch it over to overdrive to get the RPM's to go down (Which is really hard on the transmission). But when it is in the regular overdrive mode it seems to be fine. Also when it is in park an i rev it up it will stick and i have to shut the truck off to get the RPM's down. The truck has a chip in it i dont kno what it is i bought it with it, so i thought that maybe that was the problem, so i took it out and it still has the same problem. If anybody knows anything about this and knows how to fix it PLEASE let me know.

 

My first recommendation would be to check the the APPS (Accelerator Pedal Position Sensor) and the FCA (Fuel Control Actuator).

Are there any codes coming up? CEL?

 

I have a 2004.5 also mine does the same thing in park it revs up then waits for a little while 5- 10 seconds then idles down to 1500 rpm then just stops at 1500. I tap the brake pedal it goes back to idle. Strange i know I really don't know what is wrong I just figured that's how it is. Also check the floor mat you may have it bunched up the fuel pedal make sure the cable from the pedal to the brain fart i forgot what they call it. throttle control box mounted on the left of the motor that throttle cable goes to it make sure its not kinked or anything.

 

Wear is the APPS and FCA located and how would i check them? No there is no codes as of now.
When i rev it up it will not come down at all i have let it set there for about a min and it would not come down i tried everything including hitting the brake and nothing would work except shutting it off. I have checked the throttle control box and everything looks and works fine

 

AAPS that's the what I was talking about. its mounted on the left side of the engine. driver's side. I am sure that would set a code if it was bad. It does it when it's gear also Right? I will go with the AAPS is bad. But wait till other people reply. I am not the greatest mechanic on dodge trucks you give me a 5.9 b in forklift I'm at home with them. I don't have a AAPS of our engines. its all in the pedal.

 

It dont do it when it is just in the reagular overdrive mode or whatever, but when it is in tow/haul mode it does do it.

 

What you really need to do, unfortunately, is bring it to the dealer and get it hooked up to the DRBIII and see what's going on.

Otherwise you're gonna be doing a lot of guessing.

Getting it checked out is usually like a $65 diagnostic fee.

I'm betting what you're gonna find is a sticking FCA. It's located on the CP3 (injection pump).

It's held in with 2 small screws. Just disconenct the plug on it, undo the screws and pul it out.

When you shake it, you should hear it rattle. If there is no rattle, it is likely stuck.

 

I agree with coaltrain take it in. check what he said to check. Although i got a new pump on their I have never tried to rev it up since to see it mine still stays at high idle.

 

Ok i will take it to the dealership an ask them to hook it up. Does all the dealerships have a DBRIII? Also if it is bad do you have any idea how much a new FCA?

 

yes they all should have one. If its bad then get a price only. then get back with us. by that time I can find you one cheaper. can you install it yourself?