I'm getting sick of it. I'm on vacation right now at the coast and as I drag my boat through the rv park in 2nd gear with very little throttle it surges and bucks around. The symptoms are intermittent though, as in sometimes it does it sometimes it doesn't. If I go up to third and let just the idle pull me around it won't do it, but surges around with the slightest amount of throttle being applied. The only other times I've experienced a surge is when it's cold out and going 60mph or so on the highway then it starts going up and down.

I am not getting any codes and I don't have any programmers. I have a LBZ mouthpiece and Tx Cai but the truck did it before it had those mods. What is the fix for this?

In times past there has been discussion on this form about "Parking lot surge". Seems to me there is a ECM update to solve this problem.
Also, sometimes I have to wedge my foot against the trany hump to avoid pedal bounce. Just a few thoughts.

I belive it is your fprv going out. not a big deal, mine would surge at about 1300-1800 rpms and not at idle. juts annoying

Definitely sounds like FPR Fuel Pressure Regulator (not the FPRV, different part)........it will cause a low speed surge. Mine needs to be replaced (101k) but if I run a good quality fuel additive (Stanadyne, etc) it goes *almost* entirely away.

FPRV is a pressure-valve failure will cause fuel pressure not to be maintained under load or severe duty (ie, pulling a trailer up a hill) and will throw a P1093 code;) Ask me how I know!

Cheers!
Ben

sorry, was thinking the right part, just typed it wrong

Do you use fuel lubricant? This is a much less expensive fix that you could try to see if it calms down the surging. I had what sounded like a noisier idle recently; not terrible, just more clatter; I dumped a bunch of Stanadyne in the tank and then fueled it up with #2 at the local station. seemed to not only quiet it down some, but also seemed to get rid of the surging [mostly] still does surge every now and then.......

If you cannot get Stanadyne, then Wally-World sells 'PowerService' which is an 'addititive' just like Stanadyne.

Well I know for sure it's not the parking lot surge being caused by pressing the pedal because I'm traveling on flat concrete and my foot is not moving at all.

I will try some additive to see it goes away. Is there a way to test the FPR to know for sure before just replacing it?

Pick an additive with *good* lubricity.........there is an additive study here on the board someplace, you need something good 'n slippery, run a couple tanks through, and see if it helps.

PowerService was not good enough to cure my problem, so I am running something else (sorry, can't remember the name)........

Ben

"Well I know for sure it's not the parking lot surge being caused by pressing the pedal because I'm traveling on flat concrete and my foot is not moving at all."


The two are differents things.
One was a program update to the ECM, that a lot of us had done under GM warranty. I forget now exactly what was reprogrammed. Just wondered if your's was done? I think there was a TSB on the matter.
Second, usually only on rough roads. That throttle can be responsive.

Just trying to suggest the cheap things before you throw money at it.

mines had the low speed surging but its only done it once pulling the boat around at about 10 mph it went away with more speed and never really worried about it. Maybe it was a hint that something is starting to go out.

i don't know if i fall into this boat or not. what mine is doing is that when i pull up to a stop sign right as the truck stops it will give a surge or a pulse or something hard to describe. it will repeat this about every 7 to 10 seconds. it gives a small puff of smoke on a hard take off and i haven't noticed any power loss as of yet. as far as i know the truck is bone stock. it is an 05 chevy CCSB and all i have done is remove the cat. it is a cali truck if that makes a difference. we have only had the truck about a week and it just started doing this the other day. i have not done the ice pick fix or anything else like that yet either. im new to the lly, my truck is an lb7 as my sig shows.

Dumb question perhaps... but how long has it been since you replaced your fuel filter? A dirty fuel filter will cause all sorts of problems.

As for Power Service not being "slick" enough... that may well be; but I'd suggest you use enough of it to make a difference. Might try a full 32-oz bottle in your tank - that stuff has been known to perform miracles if you get the dosage up high enough.

Good luck!

The two are differents things.
One was a program update to the ECM, that a lot of us had done under GM warranty. I forget now exactly what was reprogrammed. Just wondered if your's was done? I think there was a TSB on the matter.
Second, usually only on rough roads. That throttle can be responsive.

Just trying to suggest the cheap things before you throw money at it. __________________

I'm wondering if my ECM has been updated as well. I took it to the dealer about a year ago because I was having a bad miss at that number 2 injector. I did the ice pick thing and it still missed but I did find if I move on the wires it would improve/worsen the condition. I explained this to the dealer and they couldn't find anything wrong (figures). They did tell me something was done to the computer but I'm not sure if they updated it or not. It has not missed in a full year now. I ended up getting my truck back with the dual mass flywheel hanging on by 1 rivet so I gave it back to them to fix under warranty and haven't been back since. I wouldn't mind taking it back to them but the jerks don't appear to know how to drive a 6 speed and I'm afraid of them tearing it out again.

Appreciate the responses

Dumb question perhaps... but how long has it been since you replaced your fuel filter? A dirty fuel filter will cause all sorts of problems.

As for Power Service not being "slick" enough... that may well be; but I'd suggest you use enough of it to make a difference. Might try a full 32-oz bottle in your tank - that stuff has been known to perform miracles if you get the dosage up high enough.

Good luck!

I'm due for one in about 7k miles. I'm going to Wally's today so I'll try the bottle of powerservice.

on my truck i have just put a new filter on the truck right after we got it last week. i have used the power service on it once and ran out so i haven't put any more in. i guess i'll try that agian first.

I have a 2004.5 LLY. Darn thing did the parking lot surge since new. It really didn't annoy me until this last winter and just the last couple of weeks where it would surge at stop lights and backing into the garage (almost lost another mirror).

I read the posts about surging, called up Hucksdorf, ordered new Fuel Pressure Regulator and just installed tonight (that was an experience).

Surge is now gone! Truck idles very smooth! I even put on a Finger Stick that I had laying around for the last three years (no more DTC EGR fault codes)

Replace the Fuel Pressure Regulator!

what exactly does the finger stick do?

tehbald,

I'm not an electrical expert on the "Fingerstick", but what it does is send "pseudo" signal to the ECM that the EGR has sufficient flow. By doing this the truck does not record DTC's for this fault. I also believe by preventing these faults the truck idles smoother. My conclusion on this is when I had my Predator programmer plugged in before the "stick" mode and when I erased the EGR Insufficient Flow DTC the truck would idle smoother.

Since your truck is an 03 LB7 and you don't have an EGR not sure what it would do for you.

Brian

i have an 03 but my dad has an 05 cali truck. thats the one that im having trouble with right now. just don't have it added to the sig yet.

Well I dumped 32 ounces of Power Service and ran almost all that through 34 gallon tank on the way back from vacation and it didn't help any. Also, about half way back I made a pit stop and shut off the truck then started back up and noticed the engine light was on. So I'm getting the little engine light which I'm sure means it's setting a code but I don't have a scanner to pull the code. On my old 93 I could ground 2 pins and watch the light blink and that would tell me what code the computer set. Not sure if there's a way to do it on the newer trucks.

I have a 2004.5 LLY. Darn thing did the parking lot surge since new. It really didn't annoy me until this last winter and just the last couple of weeks where it would surge at stop lights and backing into the garage (almost lost another mirror).

I read the posts about surging, called up Hucksdorf, ordered new Fuel Pressure Regulator and just installed tonight (that was an experience).

Surge is now gone! Truck idles very smooth! I even put on a Finger Stick that I had laying around for the last three years (no more DTC EGR fault codes)

Replace the Fuel Pressure Regulator!

Is that a factory replacement part or an aftermarket thing? I heard something about racing valves but not sure if that's the same part I read about somewhere else. I'm wondering how hard it is to put on? I have quite a bit of mechanical experience, but not with diesels.

I went by autozone today and got the computer scanned and they came up with only one code "Cylinder 4 misfire."

Probably unrelated to the surging but who knows.

Quote:
I have a 2004.5 LLY. Darn thing did the parking lot surge since new. It really didn't annoy me until this last winter and just the last couple of weeks where it would surge at stop lights and backing into the garage (almost lost another mirror).

I read the posts about surging, called up Hucksdorf, ordered new Fuel Pressure Regulator and just installed tonight (that was an experience).

Surge is now gone! Truck idles very smooth! I even put on a Finger Stick that I had laying around for the last three years (no more DTC EGR fault codes)

Replace the Fuel Pressure Regulator!
Is that a factory replacement part or an aftermarket thing? I heard something about racing valves but not sure if that's the same part I read about somewhere else. I'm wondering how hard it is to put on? I have quite a bit of mechanical experience, but not with diesels.

Factory replacement. I found a post in here that led me to Hucksdorf Diesel in Wisconsin...approixmately $162 +shipping. It is one pain in the *** to get at and you need to find a 2-3" T25 bit. I ended up using a 1/4" air sidewinder and one of the bolts is in a blind location. I ended up taking off the air intake, EGR, manifold air tube to manifold, some electrical connectors. After reassembly I had to "prime" the fuel system to keep it running and then ok. Not for the timid.

http://www.hdiesel.com/product.asp?id=139

Brian