Engine idle & exceleration problems

[bestbuy19]

I have a 2007 Dodge Ram 2500 5.9L Diesel Automatic with a Super Chip tuned computer in performance mode.

When I stop at a signal in gear the idle drops to 500 rpm, when I release the brake the engine revs up to about 1500 rpm then drops back to 750 without ever touching the accelerator. Then when I apply the accelerator it takes off really slow, like it was stock with no chip installed. The shift from 1st to 2nd seems like it is shifting harder than normal with little acceleration. When I am stopped with the brake on in gear and try to raise the rpm of the engine, no response.

Sometimes the rpm stays at 750 rpm at a stop and accelerates normal like it should.

I have replaced the MAP Sensor and air cleaner and still have the problem.

 

[Mobius1]

Have you tried running without the tuner and see if problems persists?

 

[cerberusiam]

Try removing the tuner and see what happens, Have it scanned for codes to see if there is anything obvious. Offhand, possibly APPS issue or Torque converter in the trans is pooched.

 

[bestbuy19]

Dean,
Had not tried removing the tuner, will try tomorrow. Someone suggested that it might be the FAC sensor. It has not been giving me an indication there is a code (no engine light).

 

[bestbuy19]

I'll remove tuner tomorrow. It has not been showing any code on the dash but, I will have it scanned also. What is the APPS? I'm hoping it is not TC, expensive. The dealer replaced the TC twice under warranty. When I had problems with the TC it didn't act like it is now.

 

[cerberusiam]

APPS is the drive by wire control, basically a big dual rheostat. Its on the firewall in your truck and pretty reliable but stuff happens.

These CAN Bus trucks you have to scan for codes to know for sure. Not everything will set a CEL.

 

[AH64ID]

Sounds more like a TC to me as the idle shouldn't be effected by a bad TPS signal on an 07, but stranger things have happened.

Are you running a 100% stock trans on the performance mode? 48RE's aren't known for their above stock power holding abilities.

 

[bestbuy19]

I've been running the Super Chip tune since 12,000 miles, it now has 109,000 mile on it. The TC and trans were rebuilt at 59,000 twice in one week. The dealer didn't do it right the first time and had to do it over. As far as I know the trans is stock.

 

[cerberusiam]

The TC and trans were rebuilt at 59,000 twice in one week. The dealer didn't do it right the first time and had to do it over. As far as I know the trans is stock.

That makes absolutely no difference if they used the same crappy parts that fail all the time. You have 50k on the trans, the TC is a likely culprit.

 

[bestbuy19]

Took Tuner out, problem still there.

 

[Mathes308]

I'm with cerb, might be able to save the trans by inspecting the torque converter.

Poor 48re, always getting put down.
On its behalf the 727 has been it a crap ton of vehicles, the orig engineers probably never thought it would be taking cummins style abuse

 

[bestbuy19]

I detuned the truck back to stock and had all of the codes read and nothing shows up on the readers. I still have the idle-rev problem.

 

[AH64ID]

Sounds like a transmission issue.