05 6.0 WONT RUN!!

[cflowers169]

Okay guys, need to pick your brains! 05 2500HD 6.0 Gas, P0300, acts like starving for gas but has good pressure, started at 1/4 tank then at 1/2 tank and now it is doing it with a full tank! Will crank and crank but will not fire, like not getting gas. When it finally runs, you have to keep your foot on the gas because if it dies it will be hours or the next day before you get it to start again. CPS was changed before the ECM died. I have replaced the ECM, truck died running down road and all electrical shut off! New plugs, new wires, replaced both knock sensors and put in replacement intake gasket. found a clogged injector and replaced it. Ran pressure test and fuel pump is great. We are stumped!

[NitroCherokee]

Fuel pump is great? What is fuel pressure? Have you pulled the line at the rail and verified flow? You may have 60 P.S.I. of pressure but not flowing much fuel i.e. clogged filter

[cflowers169]

Yep, 55p line at rail was verified, even had known working fuel pump and swapped them. still no change.

[NitroCherokee]

55 PSI is NOT a good pump!!! and IS your problem

[cflowers169]

dealer and mechs said 55-60 is target and it was low end but it was good. What should psi be then?

[NitroCherokee]

Spec is 56-62 PSI being at 55 I would all but guarantee that is your problem

[NitroCherokee]

I am the guy that the dealers call when they can not figure this stuff out, if that thing only primes to 55 PSI it is going to cause problems

[txab]

Spec is 56-62 PSI being at 55 I would all but guarantee that is your problem

+1

 

A pound or so off can make a big difference. Did you check the replacement pumps pressure as well? Key on, engine off

[cflowers169]

No we didn't, will check it this evening.

[Duelin]

Check the ECM harness where it is routed along the left side frame rail around the upper control arm. Make sure it is not rubbed thru the harness and causing a short.

[cflowers169]

Will check harness as well.

[txab]

Also when replacing an ECM, a security re-learn and crank re-learn are often required.

[cflowers169]

The dealer did ecm programming will check on the re-learns though.

[cflowers169]

well, pump is ~58 psi with no bleed off. now dealer is saying possible tps, they supposedly replace quit a few of these. ecm harness looks good. supposedly did re-learns as well.

[NitroCherokee]

I think you need a new dealer...............