jerky 6.5

[matuva]

Hi,

we have a 6.5 experiencing erratic revving, especially when tranny is on D or rear position, parked or while cruising.

Nothing happens when on P or Neutral.

The engine idle and run a bit rough, but we found, by doing injector balance with AE scanner, that injector # 6 does not respond to balance, not sure wether is has failed (stuck opened or closed) or if it is the IP failing.

Enclosed is a screenshot of the AE screen while scanning for DTCs.
There are DTCs refering to IP, and others to tranny.



What's your opinion guys, especially about erratics revving which are a bit dangerous...

 

[kojo]

There has been some rare cases where wire harness has been damaged and that has caused really weird symptoms, is it possible there could be some shortages which causes erratic revving?

#6 not responding to balance needs that injector checked, if you dont have tester you can chaange it to other cylinder and see if problem follows injector.
I have heard once IP broke so one cylinder was missing (must be fault on rotor) but before claiming IP faulty you should check compression from #6 if fault doesn't follow injector.

 

[matuva]

I will tell the owner to check the harness.
I also told him to swap injector # 6 with a good one.

Any opinion about trans code and the fact the engine revvs only when trans is engaged on D or R, and nothing when on P or N ?

 

[WarWagon]

The engine moves in the frame in D or R. A wiggle test of the wiring harness is in order as power train movement fixes or breaks a wire/connection. Shifter hitting the throttle wires? Trans connector may have issues.

 

[Brooklyn Tow]

Swap PCM/ECM.....PMD.....Sounds electrical, GROUNDS.

 

[matuva]

The injectors which are on thengine were changed last year.
In fact, those were marine medalions which start leaking less than 3 months after they wer put on the engine.
They were pulled out, a local shop change the nozes to Bosch OEM ones (or said so :rolleyes5:, but I have doubts).

So, let's say injector # 6 is carboned, or sticky, or even plugged; could this have damaged the IP ?

IIRC, the IP send fuel to injectors at around 2 000~2 200 PSI, so could this have damaged rotor or other internal in IP in case of a clogged injector ?