01 duramax has slight surge at idle???

[Vandermax]

My friends 01 has developed a loopy idle, and the fuel filter has been changed every 5,000 miles. The dealer flashed the computer, and said the surge was from the filter. Then they said it was all better, but when he picked it up, it was still there. Other than the loopy idle, the truck runs awesome, and does not smoke.

[More Power]

Welcome to the BB!

GM considers a 100 rpm variation at idle to be within specs... If it's not the fault of the fuel filter and the truck has the most recent ECM flash, the surge is likely due to the fuel pressure regulator (FPR), which is a component part of the Bosch high-pressure fuel injection pump.

Jim

[madmatt]

to add to Jim's statement....it is servicable seperate from the pump (no need to replace the whole pump)but the end of it needs inspected for contamination. If any is found the pump shuld be replaced. I've known people to just R&R the FPR and just add a little fuel treatment to the next few tanks.

[copperhead]

...and, if its still under warranty, the FPR is a $0 item (under the emission warranty), not sure about the pump but I think it is too. If they just do the FPR don't let them take $100 from your friend.

[Jimamatic]

Had the same problem with my 01. It was loping enough that it would surge forward a bit with light brake pressure at a stop light. The dealership found it to be out of spec and replaced the entire fuel pump, which at the time (2002) was the fix for the problem. I guess now they just replace the FPR and go from there. It was covered under warranty. Have'nt had a problem since.

Jim

[madmatt]

the earlier repairs got a whole pump since the fpr wasn't available by itself.

[Vandermax]

Thanks guys!!he has it at the dealer now. I will let you know the outcome soon!!!

[Vandermax]

My buddy just found out from the dealer that the fuel preasure regulator is on the frits. Will take 4 days to get one and then he will take the truck back in to have it fixed. You guys were right!!!!Thanks!!