Engine/Transmission (1998.5 - 2002) Idle and 1400 RPM problem

[GYanko]

My son has a 2001 Dodge 2500 cummins It idles fine and it runs at 1400 RPM these are the two speeds you get when press the peddle down. Has anyone had this problem and how do you fix it? He has changed the injection pump and no difference.

May 13 2009

We hauled the truck to a diesel shop, he put the scanner on and there is no comunication to the pump, showing no rpm. what would this be?

I'd like to thank all who are helping me with this problem.

 

[GYanko]

trial this

 

[Midnite]

Do you mean that when you give it full throttle in neutral (or park), that you only get 1400 rpms?

If so, I've never seen anything like that so I'm not sure what it could be. I think even in limp mode (the computer has trouble sensing boost and so severely limits fuelling) you could get higher no-load rpms than that.

I'm curious to see what others have to say about this one.

Mike

 

[WestTN]

APPS? Or, are you saying the truck runs okay, but the tach just doesn't register?

 

[JLandry]

Yah... I'd suspect the APPS (the throttle position sensor) too.



John L.

 

[WestTN]

I should have thought of this first. Do the key on-off-on-off-on without engaging the starter and read the codes from the odometer. Then check those codes in the 911 forum/OBDII codes list. That should get you on the road to recovery.

 

[GYanko]

The motor will only idle and do 1400 RPM and the tach shows the same

Doesn't matter where you hold the peddle it does 1400 rpm and when you let go it idles.

 

[JLandry]

The motor will only idle and do 1400 RPM and the tach shows the same

Doesn't matter where you hold the peddle it does 1400 rpm and when you let go it idles.

Boy that sure sounds like a failed APPS. If it is, then it's a snap to replace...



If you go to a Dodge dealer or most auto parts stores, they're going to try and sell you the entire *expensive* APPS assembly which includes the big cast bracket, the accelerator bell crank, and the TPS (Throttle Position Sensor) bolted to the side. All you need is that little throttle position sensor.



You can buy one for about $120 from user "timbo" here on the forum. Contact him via Private Message for details.



Blue Chip Diesel now also sells the same for $175.



After installing the new TPS, don't forget to turn the ignition switch on (don't start), then slowly press the accelerator pedal all the way to the floor, slowly release it, then turn the ignition back off. This allows the ECM to "learn" the full voltage range of the TPS.



Good luck,



John L.

 

[GYanko]

We hauled the truck to a diesel shop, he put the scanner on and there is no comunication to the pump, showing no rpm. what would this be?

I'd like to thank all who are helping me with this problem.

 

[HBarlow]

No commication to the injection pump sounds like a dead APPS but I experienced a number of failed APPS modules and my truck always went to idle rpm and ignored the accelerator pedal when one failed.

 

[GYanko]

This one will idle and jump to 1400 rpm that's the only two.