No it idles fine, no surge, or deviations in pressure. Thats why I asked if a high pressure leak is associated with irratic idle. Im leaning toward a supply side issue or just a weakening CP3. But we will do a bottle test. Ill let you know what the result is
LBZ: 120k mile lbz with low fuel rail pressure code
- Thread starter diesel53
- Start date
New here - this is my first post, and this thread seems appropriate for my issues.
I have an 2006 Duramax Silverado 3500 with 230k miles. Stock fuel system. The fuel filter assembly and soft lines on the suction side have been very recently replaced.
The Problem: At idle the truck surges. Sometimes worse than others. On occasion the surge is enough for the truck to jump forward if it is in gear and I'm not on the brakes. It sometimes throws the low fuel rail pressure code and goes into limp mode. It also throws a P0621 "Generator Lamp/L Terminal Circuit" on occasion but not sure if it is linked to the surge issue.
The fuel rail pressure normally build to 26,000 PSI when on the gas so no issues building fuel pressure. Here is a graph of fuel rail pressure at idle with the truck in gear. The peaks correspond to the high RPM surge. From memory - this problem seems to happen at idle/low RPM.
Best guess of what the cause? This is driving me crazy.
I have an 2006 Duramax Silverado 3500 with 230k miles. Stock fuel system. The fuel filter assembly and soft lines on the suction side have been very recently replaced.
The Problem: At idle the truck surges. Sometimes worse than others. On occasion the surge is enough for the truck to jump forward if it is in gear and I'm not on the brakes. It sometimes throws the low fuel rail pressure code and goes into limp mode. It also throws a P0621 "Generator Lamp/L Terminal Circuit" on occasion but not sure if it is linked to the surge issue.
The fuel rail pressure normally build to 26,000 PSI when on the gas so no issues building fuel pressure. Here is a graph of fuel rail pressure at idle with the truck in gear. The peaks correspond to the high RPM surge. From memory - this problem seems to happen at idle/low RPM.
Best guess of what the cause? This is driving me crazy.
