Understanding LB7 Injector Failure

[rayount23]

OK guys (and Girls),

New to the forum, and I am reading much very helpful info on the issues for my newly acquired truck.

I bought an '03 Duramax (got a great deal), that is emitting white smoke during idling, and some on acceleration. I have read about the cause of the smoke, and am planning on replacing the injectors. What I have read is that the injectors become damaged due to contamination in the fuel, water, etc. - besides their faulty/poor design. I also plan on upgrading the filtration system down to the 1 micron level for longevity and adding a lift pump. What I would like to know is two things:

Is there an upgrade for the HP fuel lines (I have read that the lines corrode an introduce contaminants). It would seem as though someone would have built some stainless steel lines to address the corroding issue.

Secondly: if the injectors are, by the description of the damage to them by the contaminants, introducing additional fuel into the combustion chamber at any given moment, why the outstanding fuel mileage (like 30+ mpg), it would seem that the system would be "wasting" the un-burned fuel, therefore reducing the mileage instead of increasing it.

Any thoughts or comments would be appreciated.:thumb:

Thanks,

RAYOUNT23

 

[blk smoke lb7]

1St off you would be hard pressed to find anyone getting 30 mpg with a d max, It just doesn't happen.If you are going off the information center, DON'T it's not accurate at all if you have some sort of tune in it which brings me to my next question is there a tune In it? It could be a tune programmed in the ecm and you don't know.Lb7 injectors suffer from heat becAuse they are under the valve covers and the original injectors I guess didn't have a hardened ball in there and after time fuel would leak past them.Better filtration would be great and would for sure help with longevity.

 

[rayount23]

Thanks blk_smoke_lb7 for the advice.

I will do some real world checking on the mileage. I do know on my ride up from Dallas to WY, I drove for 400 miles on a half a tank. That = 400/17 =23.5 mpg +/-, and that was at 75 MPH! That was real world calculations at the fuel stop!?.

Anyway, appreciate the feedback. I do not know I there is a tune in it. I did install my Bullydog PMT from my '06 Dmax that was wrecked a few years ago. Just happy to be back in a Dmax. They are about as much fun to drive as an old vette or camaro.

RAYOUNT23

 

[Chevy1925]

like Scott said, no way your getting 30mpg unless you do all downhill driving .

While good fuel filtration is very good for the health of your fuel system, it is not the direct cause of your injectors failing. No one has yet to fully prove that this is the case. I ran a stock filter and my air dog filter (2 micron), a quart of 2 stroke oil on every fill up and a bit of power service diesel kleen every so often and i still had bad injectors at 64k on them.

it all comes down to design IMHO, but again this is only opinion. The first gens were prone to cracking housings, once that was addressed it came down to bad ball and seat setups where the older ball and ball seat are very prone to etching and allowing fuel to leak by. the newer chromed/harden setup seems to last much longer. i only have 10k on these new ones so time will tell but im still ready to replace them when the time comes in 60-80k. The heat under the valve covers does not help them either like scott stated.

So people can sell you on snake oils or filter setups but untill i have a third party fully prove this is the issue, ill take it with a grain of salt

 

[dirty_max]

hows a rainbow made? hows a posi-trac rear end in a plymouth work? it just does...

 

[THEFERMANATOR]

Also don't forget there are SEVERAl different LB7 injector failures. Tehy don't all suffer the same type of failure. Some have the actual ball in the return valve wear, others have teh ball seat erode, others have solenoid failures, and then there is just plain old fashion tip wear.

 

[rayount23]

Thanks Guys,

As I research and ponder the options, and as the truck has over 300K, i just want to make sure I do all that I can to perform the appropriate work to bring the truck as close to original design with any newer improvements that would extend the life of the truck. I appreciate all your input and look forward to learning more in the future.

I love these trucks and during my hiatus from the club, I sorely missed the performance and capabilities of them. My son is heading toward an education in Diesel Technology at MSU and he also wants to get a DMax. This forum is a great help and learning tool, and yes, I appreciate the wisecracks and jokes. Makes it fun!

Thanks again, and looking forward to more.

RAYOUNT23

 

[Chevy1925]

All id suggest is a lift pump and filter setup, regular maintence, watch your balance rates and for that haze, and enjoy it!

 

[OregonDMAX]

hows a rainbow made? hows a posi-trac rear end in a plymouth work? it just does...

why is a sunset good? why are boobs good? haha

as said above, a lift pump and good filtration is the best thing you can do for your injectors hands down.

 

[RPM Motorsports]

Luckily it's an 03 and you have options, other then feeding it injectors. Do some research on swapping to a newer year/version engine, especially since its a higher milage motor.

 

[rayount23]

RPM,

That was our thoughts exactly. If it comes to it, we could do an LBZ swap (I had an '06 that was wrecked), and I loved it. Figure, I'd let my son make a project for a swap in his Diesel Tech program and get my moneys worth out of the tuition - LOL. Even inclusive of the cost of a swap, the deal we got would still be 1/2 price of a market truck with "standard mileage". Besides, I can have my son build a great motor with some additional giddy-up and fortify it. I will be looking soon for a replacement motor, etc.

Thanks again guys, and I like Oregon DMax comments, boobs ARE better than rainbows (when appropriate) - LOL.:thumb:

Keep 'em smokin'

RAYOUNT

 

[rayount23]

OH, yea, and again, anyone ever heard of upgraded HP fuel lines for the '03? Or do I just clean the ones I've got?

Thanks,

RAYOUNT23

 

[rayount23]

Also,

Does anyone recommend a supplier for new/reman injectors? Are there OEM/originals out there for sale? Or newer injectors that are updated?

Thanks,