Subject: | 6.6L LB7 No Start, Loss of Power, White Smoke |
Models: | . |
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
01 02 03 C/K 6.6L LB7 no start, loss of power, white smoke
Use J-44638 - Fuel Pressure gage to:
A. Plugged fuel filter.
B. Pinched or collapsed suction hose between injection pump and tank.
A. Leak at quick connect fittings
B. Loose clamped hose connections
C. Fuel filter connections
D. Fuel filter bleed screw not secure
Common gage readings:
Engine Speed | Gage | |
---|---|---|
Idle | 1"- 3" Hg VAC | normal |
3000 RPM no load | 3"- 5"Hg VAC | normal at operating temp |
Hard accelerations | 6"-10" Hg VAC | normal |
With the engine off and priming the fuel system by pumping the hand primer on the fuel filter, you should be able to get 10 PSI on the gage. This pressure will slowly drop to zero. A normal bleed down time is 2 minutes. If pressure drops quickly after priming the system, suspect a leak between the fuel filter and the injection pump.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
(01, 02, 03 Chevrolet Silverado/GMC Sierra 2500 HD)and (01, 02, 03 Chevrolet Silverado/GMC Sierra 3500)