Hi all,

My 01 after sitting at an idle will start to surge or oscillate. Sometimes it gets bad enough to push the truck foward a little when waiting at a light. What would be the most likley cause of this. This is the only symptom. Hower I am new to this truck and it had 79k when I got it. I suspect it may be lacking a little power.As I test drove anther and it always wanted to break the tires when accelerating on turns. Mine does not seem to have this punch.

James

very common problem ... it is your fuel pressure regulator it is mounted at the back of the injuection pump .... you can buy the part from vendors on this site. I think vendor is Merchant Automotive at http://www.gmdieseltech.com/store2/

I had mine replaced after a long fight with the dealer.:blahblah:

good luck. :)

my 01 has the same dill and it seems like it doesnt have anything pushing those back tires but its feels better than the gasser. maybe the engine sounds better thats for sure

I had the exact same symptoms on my '01. As AJK Bell said, the culprit is more then likely the FPR.

01's are now coming off warrenty, if yours was put in service after 8-01, you may get lucky as far as warrenty goes. I was out of warrenty and did the job myself. It worked like a charm.

Thanks for the replies. Steve how can you find out when your truck went into service. Also how long did it take you to do the job? Did you have to buy the regulator for $400? Mine is at the dealer now and seems to be, being left on the side without being worked on. I called at 3pm and they said they had no status on it. I was thinking that maybe I could talk them into giving me the regulator and I can install it. Im sure that its just the labor that they dont want to provide. I would think that Bosh or whoever makes the regulator is footing the bill for the part. No?

James

Yeap, Fuel Pressure Regulator Valve. Mine needs to be done as well...):h

My 2001 GMC has this problem also. Besides beng annoying, is there any other negative effects on the motor?

Hi Guys,

Can anyone advise if the faulty FPR will hurt performance. Besides the surging idol. I have had my truck at the dealer for two days now and they seem to be just leaving it on the side without anyone working on it. They keep telling me they are swamped and dont have any mechanics available. I am starting to get a bad vibe about the whole thing. Also wouldn't ya know it. The engine warrenty expires 8/8/06. Just a few days left. Could the the stealer be that diabolical?

James

Hey just going through this problem know how do I know if I;m still under warranty? Where do I find that info.

out of warranty at 100,000 miles

Also, a little additive will lessen the effects. Power Service every other tank keeps mine happy and surge free.

Yeap, Fuel Pressure Regulator Valve. Mine needs to be done as well...):h

I'm also on the same boat as you guys. But how do you tell the dealer that the FPR is the problem after they look at it and say they can't find anything wrong. Last time my truck was at the dealer the told me one of my injectors were borderline on going bad. Do I just request them to change all of the injectors? I thought I could deal with the surging idle but lately its been annoying the hell out of me.

If it has the surging idle I would take it in and say I think the FPR is going out I have a surge at idle that goes away once moving. They should find it. On the injectors idk what to say there. I have not had any problems with mine and would not know what to tell you there.

Thanks aj. I'm bringing my truck to the dealer tomorrow before my warranty is up.

Dont let them tell you a reflash will fix it because it wont, been there done that. Now I just put up with the surge.

Hi Guys,

Can anyone advise if the faulty FPR will hurt performance. Besides the surging idol. I have had my truck at the dealer for two days now and they seem to be just leaving it on the side without anyone working on it. They keep telling me they are swamped and dont have any mechanics available. I am starting to get a bad vibe about the whole thing. Also wouldn't ya know it. The engine warrenty expires 8/8/06. Just a few days left. Could the the stealer be that diabolical?

James

If you had it at the stealer before end date they should honor warrenty again I reiterate "Should" good luck!!!

If the surge is caused by a bad FPR. Wouldn't the FPR eventualy get worse and also the surging idle. Is there any long term damage if the FPR doesn't get replaced?

Brought my truck to the dealer this morning and told them that my idle was surgung. I asked them to check the FPR. Later I get a call saying that the FPR was bad and they were gonna replace it. Since it was still under warranty I just had to pay the deductable. Only thing is I have to wait till friday to get my truck back.

I'm also on the same boat as you guys. But how do you tell the dealer that the FPR is the problem after they look at it and say they can't find anything wrong. Last time my truck was at the dealer the told me one of my injectors were borderline on going bad. Do I just request them to change all of the injectors? I thought I could deal with the surging idle but lately its been annoying the hell out of me.

I took a video of the tach w/ my celly and showed it to the service writer--they came back with it needing a fprv. It's in the shop right now getting replaced @ 48,5000m

My fpr was replace and the surging stopped. I installed the hypertech III on stage 2 and a light surging came back. It wasn't as bad but still there. I took it back to the dealer and he said he found a tsb on this and they have a update program to solve this.The dealer reprogram the ecm. Does anybody know if I have to send the hypertech program back to them to have the hypertech III reprogrammed since the dealer updated the ecm?

Dont let them tell you a reflash will fix it because it wont, been there done that. Now I just put up with the surge.

X2. I've got to take mine back for them to ACTUALLY fix it this time, plus get the TCM reflash done for the 2-1 downshift.

My fpr was replace and the surging stopped. I installed the hypertech III on stage 2 and a light surging came back. It wasn't as bad but still there. I took it back to the dealer and he said he found a tsb on this and they have a update program to solve this.The dealer reprogram the ecm. Does anybody know if I have to send the hypertech program back to them to have the hypertech III reprogrammed since the dealer updated the ecm?

As far as I know you will have to send it back to get it reprogramed:( .. I have a Superchip and they tell you that if this happens I will have to send it back and they will charge me for reprograming it ... seen as when you buy the programer it is only for use in 1 truck.

Good luck