When in park i pushed on the go pedal so the tachometer went up to 2k rpms.
when the tach was on its way back down i notice the tach pausing and also the motor pausing as the engine went back down to 800rpms. (paused about 3 time before it came back to idle). Now i am noticing poor mileage and that pause when i am driving it. Any ideas would be greatly appreciated.

 

Any codes?

 

just a fan clutch is showing up nothing else

 

To me it sounds like the apps is taking a crap but hold off until you get some other feed back. I could take a little while.

 

apps????

 

Go to the search button and click advanced search. After that, use the Google search box and put "apps problem" in the box. There's tons of info available from that search that will explain it pretty well.

 

Thanks i will check it out. Ill let ya know what i come up with.

 

Sounds normal if you mashed on the pedal in park. It will take a while to bleed the excess fuel off. My truck has done it since 17,000 miles. You will notice the pause while driving if you get on it and have to stop real quick. You will notice this more running a box or programmer.

 

normal behavior if you mash the pedal in park. mine has done that since day one. The computer can influence the engine speed even if your foot isn't on the throttle.

 

Hate to say it, but, injectors is a real common cause of these sysmptoms.

 

apps ??? tps throttle positoning sensor ive check the forum on this as the fix but how do you test it. I have total throttle response. As far as injectors i havent a clue, im not getting any of signs of injector failure. Unless the throttle(tach and motor) sticking on its way back down. It also idles a little rough if i hold it at 1k 1500k rpms. This week i have changed the oil,fuel and air filters.

 

You don't test it. When it gets so bad it impacts the engine running it will throw codes telling you its a problem, or, go into limp mode and derate. APPS is the same thing as a TPS, just a lot more complicated, and reliable.

The sticking is normal, to a point. It takes time to bleed the pressure out of the rail without spiking it to high so you get a stepped down return to idle. The rough idle and dropping fuel mileage is a prime indicator of injector woes.

A scanner with a Cummins module will perform a cylinder contribution test to check injection balance. You or a tech can perform an injector return flow test to asses the health of the injector. One or both of those should give you some info on where to go next.

 

Sounds like im getting somewhere!!!! Thankyou. I will post when i figure it out and let evreyone know. Best motor i have ever owned. Cant say much about the front end!!!! " No really officer i havent been drinking its my truck!"
HA Thanks for everyones reply. Could be an excuse for injectors50hp??maybee.

 

Update. Took the truck up north for the 4th. Combined city and freeway mostly city this week still getting 19/20mpg. No loss of power what so ever.
Took it to someone i know that works on perfomance gassers and boats. He owns a second gen dodge diesel. He also says the pausing of the motor is normal like everyone here said..... but mine should be much smoother on its way down. I will know more next week i have someone testing injectors.
Wonder if my fan clutch going bad could have something to do with my motor issues? Im putting my money on either the "apps" by totallyrad or "injector" by no 6 oh no.