ruff idle (APPS sencor?)

[BLoging]

the truck setting in park with the truck running the truck is shacking and the idle is dropping about 200 to 400 rpm when it stumble or surge's( i do not know what to call it, ) it is doing this about every other 10 to 15 second's, and it is shacking almost all the time when it is set in park and no foot on the petal. If i put my foot on the go petal to rase the rpm's the truck stop's shacking and the rpm's rase to what ever rpm's that i push on the petal ( harder the push, higher the rpm's). and while in any other gear and driving down the road it seem's to go away, but it will stumble once in a great wile going down the road. .

from what i can figur out from all of the post's that i can find is that it may be the APPS sencer but I am not sure!!! can any one help me out and find out if it is this sencer or from what i have given as information. can it be any thing else, like the FCA or any thing else??

 

[JJPage]

Throwing any codes? Could be a number of issues, but first check for codes.



Ideas... . dirty fuel filter, failing lift pump, failing FCA, rail pressure relief valve, rail pressure sensor, dirty injectors...



While idling, if you place the trans in drive do the symptoms stop? I am leaning a lot harder towards the FCA than the APPS, but it could also be a mechanical issue(leak) causing low rail pressure at idle, and when raising rpm's it diminishes.

 

[BLoging]

i am getting a P0148( i think that is the code number not sure though) the info the is say's with the code is high pressure rail checksum. just chacnge the fuel filter back in early september and in late october i put on a fass platnum fuel pump!

 

[BLoging]

i will check to see if that is the rite code number on thursday when i get to work and look and see if it will come back up for me!

 

[TCDiesel]

What pressure are you feeding the CP3 , do you have the factory filter canister installed?

 

[BLoging]

no i am useing a fass platnum, what ever they set a fass for the psi!

 

[BLoging]

the factory filter can is still in use, i have the fass platnum hooked to it and from it to the cp3.

 

[JJPage]

You have to determine what pressure the FASS is hitting the CP3 with, if it is too high, I believe you could be causing the cascade valve on the CP3 to open, there by causing your issues.



TCWest knows a whole lot more about these pumps than I do, maybe he will chime back in for clarification.

 

[BLoging]

from the dealer that sold me the pump he said the psi slould be about 15 to 18 psi. after i have put the pump on the truck has started a lot easyer but it still roll's about 3 to 7 time's untill it will start

 

[TCDiesel]

Is the factory filter still installed after Fass?

 

[BLoging]

yes the factory filter is being used!

 

[TCDiesel]

Just to eliminate the APPS... Disconnect batteries for 20 Minutes. Then re-connect turn key to on position (DO NOT START ENGINE) push go pedal 3 times all the way to the floor,then turn key of wait 5 seconds ,then start engine to see if this makes any change...

 

[TCDiesel]

Auto or manual?

 

[BLoging]

auto.

i was talking to a local diesel mechanic and he think's it may be the FAC and not the APPS from what info i cave him

 

[TCDiesel]

If you want to narrow it down call Me...

 

[cerberusiam]

Tyical problem with those symptoms is the FCA, fuel control actuator. APPS reset does nothing on a 3rd gen, they reset every time the key is turned on and pretty trouble free. Most of the surging and bouncing idle problems are going to be fuel delivery to the rail and thats mostly the FCA. You could try a heavy dosing of the Power Service and 2 stroke oil to see if that would free it up.



I would recommend runing the power service\2 stroke all the time to kepe things beter lubed.

 

[BLoging]

one of the other member hear on TDR informed my that it is most likey it is the fac. and i going to get a test one from him next week and see if it is the FAC

 

[Blakers]

Was there ever a resolution to this problem?

 

[BLoging]

got a new FCA and put it in and has been working great so far got about 3000 mile on and no more ruff idle

 

[BLoging]

the stumbling is back and putting up the code's of p0251 and p0148 and it is doing the stumbling more when it is hot out like at 80 or warmer and it is not a ruff idle as much this time but it is stumbling at all different time and it some time on first start up it start's on the second or thread roll of the motor and run's for about a second and then die's, restart the truck and does it again. it is seams to be the FCA again but from reading on some of the thread's that i have read that it is not the FCA, and from the test that i did by unpluging FCA wile the truck is running and then pluging it back in and timing it for how long it take's for it to recover and sound normal again and the time it took was about 15 seconds and one other test that i did was to unplug the rail pressure sensor for about two min's and and then plug it back it and see if it will stumble and then recover, but the truck just died.

so is this the FCA or the rail pressure sensor?