Duramax Power Reduction
Not sure if this is the right place to post so admin please move if needed. 96 degrees, mountains of North Carolina/Virginia. Climbing around Fancy Gap on I-77 and with no warning truck says "powe...
Forum Discussion
NMDriver2 wrote:
Silverado's have a rubber hose in a section of the fuel line near the tranny. With time, heat, and high fuel demand the hose will constrict (partial collapse) because the Silverado uses vacuum from the fuel rail to suck fuel instead of a lift pump to pump fuel through the filter and lines.
The truck CPU thinks the fuel filter is clogged or the injectors are clogged, or ??? but the result is you have reduced power. If you stop and let it sit a few minutes the hose cools down and resumes the correct diameter. The truck runs fine until you get into another hot, high fuel demand situation. Like climbing a hill on a hot day.
There is a Tech bulletin on fixing the hose or you can have a aftermarket lift pump installed or both.
This was my problem on my 2008 Duramax LMM. Hit limp mode going up a small hill with my previous (smaller) trailer. Turned off the engine on the flats and waited a couple of minutes, turned back on and problem was gone. When I replaced the hoses, one of them was collapsed and I am surprised it worked as well as it did. I have not had the problem since and have towed up some major passes in the Rockies with my fiver.
One other note, my limp mode did show a code related to low fuel rail pressure.
