pretty much lost

[Burn Down]

Ummm, not sure where to start here? Your very lost...

Not cleaning the high pressure lines is a BIG time no no. Can lead to instant injector failure...

Still doesn't mean the lines were contaminated but thanks for clearing that up. I don't feel so lost now:hug:

X2. they could be perfectly clean until you loosen them and let all the crap built up around the fittings fall into the lines. Install the old lines without cleaning them and there's a good chance you will be replacing injectors again.

I think you both misunderstood my reply. Could the lines have been contaminated? Maybe. Do you know for sure? Nope.

Nclmm made it sound like he needed to just give up and buy a new fuel system.

I would rather T/S and replace what is needed then piss a bunch of money away on a maybe...

 

[NC-smokinlmm]

Still doesn't mean the lines were contaminated but thanks for clearing that up. I don't feel so lost now:hug:..

I've never seen nore heard of any lines on a 14 to 11 year old truck not rusted/contaminated. Sorry your wrong...

They should have been soaked in Evaporust or CLR then bead blasted or at least cleaned with some pipe cleaners for gods sake. They get super nasty and most of the time the sealing surface needs a little attention as well...

 

[danzick]

I replaced mine at 65,000. Truck spent most of its life in a garage, and the previous owner flew down south for winter so I hardly every saw winter roads. They were plenty corroded and rusty even with those conditions. Some scotch brite pads or wire brushes and a ton of brake clean works pretty good.

 

[dirty_max]

i have yet to work with someone on semis who hasnt gone by the philosophy, "a little dirt dont hurt" so i wouldnt rule out installer error :roflmao:

 

[danzick]

yeah.... whats a little dirt in an engine that gets rebuilt every million miles haha

 

[bluthndr]

I own a 3500 sq ft 5 bay diesel shop and do lots of LB7 injectors, but may not know everything...

1. You are probably putting at least some injectors in, but diagnose them first as others have stated. Commanding rail pressure up and killing individual injectors/cylinders is a good start. Also check for fuel in the oil -either watch your oil level closely (daily), and/or put a drop on paper and watch how fast it spreads compared to a drop of new oil. If it's putting fuel in the oil, don't keep driving it or you could wipe out the bottom end and put an engine in it instead of a few sticks. In a VERY few cases (like 2), I have seen a stuck open injector melt a piston and ruin internal parts, and one of those two had no unusual noises, just a miss on that cylinder.

2. I only buy injectors for Dmaxes from Bosch fuel shops or GM. To the best of my knowledge GM's are Bosch reman sticks, from Bosch, in a GM box.

3. EVERYONES injectors are remans, but the vast majority of those sub $200 ones are "re manufactured" by testing returned cores on a stand, and putting new nozzles on and re boxing. I think some are not even tested, just cleaned and reboxed. As of a year or two ago, guys I trust told me they have around $160 cost in rebuilding the injector the right way, and people need to make money to keep the doors open. Less than that you are getting cleaned up used ones that have been made to look better - I have even seen some that I'm sure were glass bead blasted(!) to pretty them up.

4. The "line cleanup" needed refers to the tip of the feed pipes where they attaches to the injector body and the fuel rail. Tons of rust/scale/dirt accumulates there and falls into the "fuel in" hole (feed port) on the injector especially. For this reason I flatly refuse to replace less than 1 bank at a time on LB7s - it is a guaranteed angry customer and net loss for my shop - all the lines have to come off the bank to pull the valve cover, contaminating all 4 injectors on that side. Getting the lines' conical seat and nut surgically clean is a big deal. Congratulations to anyone who has been fortunate and got away with not doing 4 - it is just not the right call for a business/customer situation.

5. I have never seen an electrical problem cause what you describe on an LB7. LLYs and LBZs yes, but never an LB7

6. Bosch fuel shops, Merchant, PPE, and various EFI live gurus know infinitely more than me about these, but I do fix a lot of new diesel trucks with good success.

Hope this helps.

Congrats on the engagement and upcoming wedding.

 

[durallymax]

If it's putting fuel in the oil, don't keep driving it or you could wipe out the bottom end and put an engine in it instead of a few sticks. In a VERY few cases (like 2), I have seen a stuck open injector melt a piston and ruin internal parts, and one of those two had no unusual noises, just a miss on that cylinder.

2. I only buy injectors for Dmaxes from Bosch fuel shops or GM. To the best of my knowledge GM's are Bosch reman sticks, from Bosch, in a GM box.

Not saying its right, but I know of many trucks that are running great after thousands of miles of diesel for oil. It's still an oil in a way. I'm not suggesting you can leave the issue for months, but you don't need to shut it down on the side of the road and call a tow truck either. Its not going to catastrophically fail. Long term wear? These trucks rot out before the engine will see its end. Again, not a good idea to drive around with diesel in crankcase but not something that you need to immediately shut down.

GM LB7 injectors are no longer from Bosch and haven't been for a couple years according to Bosch. Regardless of that, whoever is doing them now does a good job at a great price.

 

[bluthndr]

Not saying its right, but I know of many trucks that are running great after thousands of miles of diesel for oil. It's still an oil in a way. I'm not suggesting you can leave the issue for months, but you don't need to shut it down on the side of the road and call a tow truck either. Its not going to catastrophically fail. Long term wear? These trucks rot out before the engine will see its end. Again, not a good idea to drive around with diesel in crankcase but not something that you need to immediately shut down.



GM LB7 injectors are no longer from Bosch and haven't been for a couple years according to Bosch. Regardless of that, whoever is doing them now does a good job at a great price.

All true^

Just got lazy and didn't want to type that much. By Bosch I meant remanned by a Bosch (authorized or whatever) fuel injection shop. Also have had good luck with dipaco (might be spelled wrong), but I don't know that they are available direct to the public.

In general fuel in the oil is not a huge deal, but I have seen a couple trucks develop lower end noise that I suspect was from diluted oil over a long period of time. It happens much more frequently on 6.4 Fords when guys go too long between oil changes (regen cycles put it in there). Duramaxes tolerate diluted oil much better, but are not invincible.


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[durallymax]

All true^

Just got lazy and didn't want to type that much. By Bosch I meant remanned by a Bosch (authorized or whatever) fuel injection shop. Also have had good luck with dipaco (might be spelled wrong), but I don't know that they are available direct to the public.

In general fuel in the oil is not a huge deal, but I have seen a couple trucks develop lower end noise that I suspect was from diluted oil over a long period of time. It happens much more frequently on 6.4 Fords when guys go too long between oil changes (regen cycles put it in there). Duramaxes tolerate diluted oil much better, but are not invincible.


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GM's are no longer done by a true Bosch reman facility. Who does them now I dont know, dont care either because they still work great.

The 6.4 oil issues are a bit different, while fuel dilution is fuel dilution, there is a lot more soot at work in the oil of one of those than an LB7. The LMM uses in cylinder dosing (for regen) like the strokers but the LML uses an injector downstream to inject fuel for regen. IIRC 6.4 guys have troubles going much longer than 8k or so, I've run 15k+ with just regular Delo 400LE and still had fairly clean results on LML's. Clean running engines.

True though, its certainly not invincible.

 

[bluthndr]

GM's are no longer done by a true Bosch reman facility. Who does them now I dont know, dont care either because they still work great.



The 6.4 oil issues are a bit different, while fuel dilution is fuel dilution, there is a lot more soot at work in the oil of one of those than an LB7. The LMM uses in cylinder dosing (for regen) like the strokers but the LML uses an injector downstream to inject fuel for regen. IIRC 6.4 guys have troubles going much longer than 8k or so, I've run 15k+ with just regular Delo 400LE and still had fairly clean results on LML's. Clean running engines.



True though, its certainly not invincible.

Interesting. I have been buying them from two different Bosch shops, but maybe they are just reselling at this point? Maybe they are using DiPaco as well? I know the return line and gasket kits usually come in DiPaco bags... Thanks for your input - I learned something there. I wonder why LMMs seem not to have anywhere near the issues of the 6.4s? Thanks for the input/comments


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[durallymax]

If you get Bosch ones from Bosch shops they are Bosch. They will say Bosch on them box and have a Bosch number not a GM duramax number. They usually are much more money as well.

Pensacola ships/shipped their injectors with Dipaco seal kits as well. Bosch and GM both supply copper and both o rings with the injector, the return lines are seperate though.