I am in the military and we have a newer maintenance truck, '10 Silverado 6.6 Duramax, with 10k miles on it that is having a starting issue. The truck is bone stock and cranks good and strong, just replaced the fuel/water separator and fuel squirts out when the bleeder screw on the filter housing is opened. Also, the O-rings on the F/W separator are seated and the WIF sensor appears to be in good shape as well as the fuel head. The truck was on its way back from the field when it died out so I don't believe the notorious WIF sensor crack happened randomly while driving.

We have not discovered any leaks anywhere in the system, however it will only start after we pump up the primer until it is firm and only idles for a second before dying, but that pressure will leak down if left for a few minutes. We do not have the equipment to perform tests other than a dinky scan tool to check for DTCs. I would prefer to not tear down the top half of the motor to get down to the injection pump if we don't have to. Any parts that need to be replaced will have to be approved through the command's supply department before being able to be purchased from the stealership. This process can take a couple weeks so just throwing parts at the truck that are not the problem can easily turn into months before the truck is running again. This is our only field service truck so the sooner we can get it up and running, the better. We do have an '08 that is currently down due to Chevy's recent airbag recall and linkages for the driver door handles but otherwise runs fine, is there anything on that truck that we might be able to use to diagnose the issue? Any insight that anyone can provide would be greatly appreciated.

 

i would do a filter head rebuild on it..u know were the fuel filter screws on..parts r only bout 25-30 dollars..and wile ur at it also check the fuel line that go to the injection pump for cracks or splits...scott

 

Swapped out the fuel head with one of our other trucks and now when we prime it, the truck will idle for about a minute now before shuttering down until it dies, thinking the suction side of the injection pump isn't pulling fuel, next week we will see about swapping it out. We have one truck that already has the top half of the engine torn down, but it is a 2003 LB7, does it have the same CP3 as the LMM? If so that will save a lot of time and hassle tearing down the '08.

 

So either our truck is setup slightly different or I'm doing something wrong (the latter of the two would not surprise me one bit). 5 hours into the job now and the top end is torn down including the intake piping but it seems that the turbo would need to come out in order to remove the manifold Y-pipe to get the clearance to slide the pump out, the top front bolts on either side came out no problem as did the lower front, but I can't even get a box wrench on the top rear so even if I were to get them loose somehow, I can't remove them because they're like 1/4" from the compressor housing, I haven't even tried to screw with the lower rears. Then comes the fact of how in Sam hell do I remove the pump? Is it bolted from the backside? I can feel a couple 10mm bolt back there with my fingers but my shallow socket is too short to reach, socket with the shortest extension (1/2" I think) is too long, and a deep socket is way too long. I know there are a couple Torx head bolts on the front right there at the pump, are these the ones to take out? If so, does the coolant cross pipe need to come out? Plenty of blood is now permanently a part of this truck now and I've spent a fair amount of time looking for the tools I threw across the shop as a result.