[gfressadi]

I'm stumped...

I had a fault code and have replaced two of my injectors 7th and 4th.
Prior to this the truck would spit a little white smoke at idle, intermittently, mostly after truck had been running over 30-45min.

Since then I have replaced the Injector controller, all o-rings in the fuel filter assembly, new filter and new injector harnesses. Filter holds prime.

Occasionally the enginer reves above 2000rpm but it only last for a short time (5-10 seconds) and then returns to the governed state of 2000rpm.

Like I said I'm stumped any info is appreciated.

Truck: 2001 GMC 2500HD LB7 Duramax, no mods, living in the southwest.

 

[blaineGMC]

is the check engine light on?

 

[blaineGMC]

oh my bad you said no fault codes. No 1 Change your fuel filter. If that doesnt help there may be a problem with the accelerator wires between the engine and the pedal. however that problem is very very rare

 

[blaineGMC]

somebody give this guy a hand

 

[wsmithduramax]

Check the main wiring harness on the engine, I had this happen on my 01 and never had a codes set, but turns out it was a terminal in the main harness that was pushed back in the connector and wasn't making good enough contact or check for bent terminals in the connectors as well good luck.

 

[gfressadi]

Thanks guys, I'll look at the harness tomorrow.

The check engine light did come on but didn't stay on.
Followed by a "security". But no fault code, I'm upgrading my scanner to see if there is a code but reader not catching it.

Another mechanic thinks all the injectors need to be replaced. This doesn't make sense about the limp mode or the intermiteant part.

 

[blaineGMC]

i would change the fuel filter if i was you

 

[gfressadi]

Update:

On my third fuel filter change.
Going to try switching out the accelerator rheostat. Main harness looks good as do the injector harness(s).

I'm pretty sure it's an electrical problem, rail pressure is in line and prime keeps.

Has anyone been able to do a "hard reset" on a Duramax?
the service bulletin nothing was mentioned about needing to do this, but I'm about out of options.

Thanks for all your help