Hi:

2004 2500 with 6 speed 21k miles... Have a problem with the throttle, best
way to describe it is is to include the attached graph that roughly indicates
how the engine rpm responds to throttle pressure.

The rpm will go from 750 directly to 1100-1200. You start pushing it
slowly and keep pushing and pushing and pushing rpm rock solid at 750
and BAM! all of a sudden it shoots to 1200.

This cannot be the correct behavior! This makes shifting and low speed
operations quite jerky. I guess an automatic you woudn't notice
it so much but with the six speed it is very unpleasant, and feels like it
it needlessly beating up my drivetrain.

I saw some posts from long ago mentioning calibrating the throttle
somehow. Would that help here? Is that the problem? Or is it time
for a **ealer visit? It's done this from day one just haven't really had
the time to pursue a resolution.

Thanks for any input!

 

Doesn't sound like correct behavior. It won't hurt to try an APPS reset, but more than likely you are in for a trip to the dealer. Instructions for resetting the APPS are here: https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

Would resetting the APPS be ok for an Auto? Or is this just a stick shifter fix?

 

It won't hurt anything. The electronics in the APPS sensor has been improved upon over the years. You don't hear of the 3rd Gens having the APPS problems the 2nd Gens had. Usually if we have a APPS problem, it is really broke and just needs to be shot. A simple reset usually will not do anything for it. Nothing wrong with trying though.

 

my truck does exactly the same thing, although if you let off very very softly you can get it to idle slower. When driving I can hold any rpm from 750-3500, it's just when the truck is sitting still is when it's hard to get any rpm between 750 and 1200.

 

You both need new TPS assy's.

 

Really? It is that bad? Not looking forward to convincing the blockheads
at the dealer that there really is a problem...

Will try the recalibration procedure first... maybe it will help a little. Nothing
to lose by giving it a shot! If not, off to the dealer I go....

Thanks!
Jim

 

throttle response sounds similiar to all of the 7.3 powerstrokes w/ automatic transmissions that i have drove.

 

I may have a similar problem. It doesn't happen all the time, but it seems to fuel itself up to 1500rpm on it's own. This fueling is rapid like the truck is trying to race and then all of a sudden nothing it defuels and then the pedal is in control again. It's weird and annoying when your in a parking lot.

 

I think I've had that happen also... for me with the six speed it seems to occur when I'm lugging the engine (or close to it) and hit the clutch to stop. The engine is still receiving fuel and there is a bit of a delay for it to stop and recognize that I have lifted off the throttle. Is that what you mean?

Yea I find it annoying too, but I think that is just a product of the auto-throttle or whatever it is that tries to maintain engine speed by adding fuel. i.e., the reason we can start from a dead stop in second gear without touching the gas while towing a trailer.

Don't think the two are related... but I could be wrong. anyone?

Thanks!
Jim