01 duramax has slight surge at idle???

[turbo-burb]

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.

[turbo-burb]

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

[turbo-burb]

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!!

[GUNTHER]

HI IM TURBO BURBS BUDDY GUNTHER . AND I HAVE THE O1 DMAX . JUST JOINED THIS SITE . STILL WAITING FOR THE FPR FROM THE DEALER. LET YOU KNOW WHAT HAPPENS THANKS GUNTHER

[xwing]

I have 2001 DMax D/A; it has slight surge at idle for years now, and no problems, doesn't get any worse. I actually enjoy it smile.gif it is a non-problem to me.

[Driveshaft]

I HAVE AN '01 AND ABOUT 3 MONTHS AFTER I GOT IT, IT DEVELOPED THE SURGE IDLE AND DEALER UPDATES SOLVED THE PROBLEM. IF, I STILL HAVE A SURGE,(I HAVEN'T NOTICED IT IN ALMOST 5 YEARS) IT IS SO SLIGHT THAT IT IS UNNOTICEABLE UNLESS YOU ARE BEING PICKY. ANYWAY, NO PROBLEMS SINCE THE COMPUTER UPDATES.

[xler8ion]

I have an '03 and have had this problem on three separate occassions. The surge at idle is not consistent and at times is severe. Within the last year I have had the injectors replaced, the reg replaced, one of the new injectors replaced, the fuel filter replaced more than once. Each time the problem is cured for a while and then returns. The problem has now returned again and its going back in and yesterday it coded. I had a shop scan it with me watching as the dealer cannot get it in for a week and it came up with P0308 Cyl #8 misfire. #8 injector is at .9-1.0 ms while the others are .5-.6 at idle. Off idle and through the remainder of the range all inj are even. The actual reg pressure at idle is jumping around from a low of 430 to a high of 612 at idle-these are the extremes. It also has developed excessive fumes from the passenger side front near the wheel well. Its going back in but I am sick of this problem returning...any thoughts?????

[copperhead]

excessive fumes, passenger side front near the wheel, I'm assuming diesel odor....I think that is the side where the vent tube comes out, could be diesel in the crank case.