Have there been any issues with injector wiring on the 03 Duramax? I have an 03 with 264,000 miles and have had 4 full sets of injectors replaced (under warranty) a #2 injector out of warranty. Now the #2 is setting a misfire code.

If I recall the #2 was always one of the injectors that always failed in the other failures but not it by itself.

The engine idles rough at times but is intermitten. Sometimes it idles smooth as silk until I release the brake and let it roll and then it will start misfiring. It is like a sparkplug misfiring.

Has anyone else experienced this? Anyone had a wire harness issue on a specific injector on the LB7's?

Could it be the Edge chip causing this?

Hmmmm, good thread, ive lost #2 twice now! last time i had a misfire code set too, but mine missed when i stomped on it. Wonder is its coincidence or this is a trend?

LB7 injector eaters post in!

If the same injector keeps going bad, I would look carefully at the fuel supply line to that injector. Maybe it is corroded inside and letting debri get into the injector.

Thanks....that is one thing I had not thought about.

Does anyone know of a thread that provides any info on replacing the injectors on an LB7? I am thinking about doing the replacement myself.

It is $1200 at the dealership to replace 1 injector.

Also, are the even number cylinders on the right and odds on the left like other GM V-8 engines?

my #6 seems to be the culprit in my motor for what should soon be the second set of injectors. i took off the seconday filter kit last night, but this morning #6 is back within specification!!!????!!!. It was also cooler out this morning(around 25 degrees) and it seems that it really only acts up fully warmed up and even with a 17 mile ride to work with most of it 45+ I'm not sure the truck reaches full temp. I know recently there was a thread with some pictures of a guy doing it himself in the garage, but as GM thinks, with such a pain to change out 1 injector, at a minimum I'd probably do the whole side.

Another strange thing to me about this injector is that it runs great and idles smooth. When stopped like at a stop light of sign with the brake applied it is smooth idling. If I release the brake to let the truck roll forward it gets real rough. As soon as I apply the brake it smooths out. This makes no sense to me.

Does anyone know of a thread that provides any info on replacing the injectors on an LB7? I am thinking about doing the replacement myself.

It is $1200 at the dealership to replace 1 injector.

Also, are the even number cylinders on the right and odds on the left like other GM V-8 engines?

http://dieselplace.com/forum/showthread.php?t=183224 Lottsa good info here, hope this helps!:D

Another strange thing to me about this injector is that it runs great and idles smooth. When stopped like at a stop light of sign with the brake applied it is smooth idling. If I release the brake to let the truck roll forward it gets real rough. As soon as I apply the brake it smooths out. This makes no sense to me.

Mine does the same thing. Not all the time however and it seems to be worse when under a load.

Try this, with the truck warmed up after a drive put your foot on the fuel. Just a little.... not enough pressure to even bump the RPMs, it should start the rough idle again... at least it does with mine. I think the quality of fuel also has something to do with this. I put 6 ounces of Opti-Lube a couple of fills ago and it smoothed out the idle issue. Now it is starting to come back. Let me know if you were able to duplicate the idle and smoke.

My #7 is showing a high rate, the truck goes in Tues.

Thanks for the link mytmouse.

I will try that nowake.

Thanks for the link mytmouse.

I will try that nowake.

Let me know what happens.

Nowake

Mine did what yours is doing. I had my foot on the brake and touched the accelerator like you said it it started idling rough. I also tried it in park and the same thing happened.

Mine also does the same thing if I release the brake and NOT touch the accelerator and let the truck roll at idle. As soon as I apply the brake it smooths out.

Any clue as to why this happens?

It makes me think that the injector may not be bad after all.

Tom, glad to know that mine is not the only one. For what it is worth my #7 is out of spec with the balance rate and my #5 is really close.

I have heard some say their idle smoothed out after they got new injectors.

My truck is going in on Tuesday, I will let you know what they find.

It is just so strange the way that the eng responds to these conditions.

I know and I am really surprised no one else has jumped in with some additional information for us.

Anyone? :o:

Surely we are not the only ones having this issue.

I test drove an 02 with this issue also.:eek: Anyone have a known cause?
Thanks,

I am going to take a stab at this, my 04 LB7 does not do what is being described but I have an idea.

I thought the balance rate(s) was simply an idle function, in other words the computer will try to balance out the push on the crank by adjusting each injector.

Once you let off the brake another portion of the fueling program takes over...and hence drastically different results.

Now one would expect that if you have an injector going out, it would correlate with poor balance rates.

But there have been others that have had good balance rates and still had their injectors fail. I think that is because the program balances out the idle by adding or sub from an injector but what if two injectors are bad in the opposite way...then maybe the program does not need to do anything yet they are both bad?

Just a thought.

well my trucks been in since last Friday morning. I don't think they've done much if anything as of yet, but with the 'special policy' it's a worthwhile waiting game. The upside is though free loaner car for the last few days so that's one upside.

Haven't heard squat from the dealer wondering if they just a go ahead from GM and could possibly be replacing as we speak without them contacting me first? Could life be that for me?

RonJT

Good points. I am going to have the balance rates checked soon. I noticed a tapping noise this morning and heard it occassionally in the past. With 264K miles and 4 sets of injectors at GM's expense and 1 #2 injector at mine I am not sure I want to continue spending money on injectors. I was wanting to get about 500K before trading. Not sure yet what I will do.

Tom Cobb,

Remember that white smoke is really the killer sign. Eric Merchant has posted on a high mileage truck that went through 5 injectors sets(I think...it was high) that eventually burnt the piston.

His view was that multiple injector failures eventually weaken the top of the piston because of the fuel being dumped in at the wrong time.

If you see a lot of white smoke.....then you should stop driving and fix it...in order to save your pistons. Also...when my set of injectors failed(I am on the second set 140k miles on truck, 50k originals went out)the smoke came out so bad the guy at the light next to me rolled his windows up. I also noticed a drop off in economy..about 10%.

So in summary, the key issue with the LB7 injectors is (INMHO) once you have a pretty good sense that an injector(s) is failing...get it out of there...because it could take your piston.

RonJT, thanks for you post. That does seem to shin some light on the reason why.

Our truck is going in tomorrow, I will let you guys know what they say.

My son say he saw a little puff a couple of times when he was behind me and I thought I had seen an occassional puff after stopping but nothing on the order of what I had on previous failures. It may be coming soon though.

I was returning from a trip once when one of the sets of inj went out and had smoke like you are talking about. I was ashamed to show my face and hoped a Ford or Dodge driver was no where around. There were no mesquitos near me however.

the last time I had bad injectors I was spraying yard guard all over the place. This time, an occasional puff, occasional rough idle, but a weird feeling of 'uneven rotors' when slowing <2mph to stop, but at stop she was smooth again. Last time at stop she ran rough at idle.

Anyhow injectors are being replaced as we speak, still going to sell the truck though, as much as I love it, the high cost of diesel and potential high cost of repairs with little need for the truck days, it's time to part ways.

Service writer is telling me I'm paying deductable though($100), we argued a little over the phone, realized I'm just waiting my time and printed out the special policy and highlighted the number and line of 'at no charge to the customer' which I will present when it's done but they're waiting on parts/etc. Didn't want to push it too much though because I've got a free loaner from them as well which is saving me several hundred on a rental.

Victory,

Sorry to hear you are going to sell, but understandable. Good luck and thanks for the quality straps..I love 'em.

I'm sticking with GM, but for a short while I'm going to a sedan for a while and keep the 'trailblazer' as the work horse :rolleyes: :bawl:

I've had a good 5 1/2 years with her, just got the right price at the right time. The nice thing is, in 2 years there's a new more effecient 4.5l duramax coming out that may just be the ticket. Let it settle out for a year or two like I did with my 03(although i should've waited a few more months for the LLY) and buy again.

I am NOT by any means an unhappy owner, I will miss the truck, I'll still hang out here though and watch what happens, and I'll probably regret selling my truck 15-20 times a year, especially when I'm borrowing the company 3/4 ton to do my occasional hauling and it gets a constant 11 mpg.

the last time I had bad injectors I was spraying yard guard all over the place. This time, an occasional puff, occasional rough idle, but a weird feeling of 'uneven rotors' when slowing <2mph to stop, but at stop she was smooth again. Last time at stop she ran rough at idle.

Anyhow injectors are being replaced as we speak, still going to sell the truck though, as much as I love it, the high cost of diesel and potential high cost of repairs with little need for the truck days, it's time to part ways.



Victory Red, this is the same problem as you know I am having. What did they find when they ran the checks. I know for a fact my #7 is out of spec, but I have no idea about its return rate. I have also heard they will only replace the affected injector if it in not showing the signs of the service bulletin.

You are lucky, they are making me rent a car. I asked for something I can tow with because I have to pick something up and tow it home. Enterprise does not allow towing! :mad:

I just hope they replace all 8 and take their time to do it right.

As I recall the service bulletin for the 01-03 is different than the one for the 04 models. The 01-03 they were told to replace all eight injectors.

I know there were posts on here that have copies of the bulletins.

Looks like the same one....

Document ID: 1867166
#04-06-04-007G: Service Engine Soon (SES) Light On, DTCs P0087, P0093, P1093, Low Power, No Start, Hard Start, Fuel in Crankcase (Replace All Injectors - New Strategy for High Fuel Return Rates) - (Oct 16, 2006)
http://gsi.xw.gm.com/image_en_us/gif/000/999/999/999999995.gif Subject:Service Engine Soon (SES) Light On, DTCs P0087, P0093, P1093, Low Power, No Start, Hard Start, Fuel in Crankcase (Replace All Injectors -- New Strategy for High Fuel Return Rates)
Models:2001-2004 Chevrolet Silverado

2003-2004 Chevrolet Kodiak C4500/C5500 Series

2001-2004 GMC Sierra

2003-2004 GMC Topkick C4500/C5500 Series

with 6.6L Duramax™ Diesel Engine (VIN 1 -- RPO LB7)



The question I have, if the "balance rate" is high will the "return rate" also be high?

If the "return rate" is with in spec then what will they do with the injectors with on showing a high "balance rate"?

No-Wake in all honesty I only talked to the dealership briefly on monday about the truck(when I bitched to the salesman that they're service isn't keeping schedule of keeping me informed like that said they would). The guy called, said yes they're bad, I asked if it fell under 'policy', he said he'd call back. He called back said yes, but that there would be a $100 deductable, I say no he's misinformed, I say no special policy says 'at no cost to customer' he said he's printing it now it says $100, decided not to argue at that point since my rental is free and they got my injectors covered. he did mention one was leaking, but I'd rather hear it from the mechanic, service writer, don't always trust them since they deal with so many people at at time. They were waiting on parts, but thought they'd have it done by today(wednesday). Will ask the appropriate questions and I'm taking in a printout of the special policy with the no charge to customer highlighted.

I'm also likely buying a new Impala from this dealership, however our price differential is $150(i'm getting a pretty good deal with rebates and GM card, but still $150 more than I want to spend). I can likely hold out to months end with my buyer on my truck and hopefully their sales will be lower again than they'd like and they'll budge. Really want the leather interior :gr_grin:

They just called me, all 8 are going to be replaced. I am picking it back up and it will be back in the shop next week for two days.

I knew it was all injectors on the 01-03 when it first came out but wasn't sure on the 04. That good news for you.

Yes it is.... but we have a run up to Chicago that leaves next Friday.

Do not know if they will have all the parts in time.

But either way, it is a great thing they are replacing all 8. I talked to my Ford service friends and they said they still do only what is needed! Thank you GM for standing behind your product! ;)