[weldersd]

I have been nosy looking for info quite relentlessly for a while now and I learned some info I would like to pass on, according to an ex-bosch engineer to determine if you have the "updated" lb7 injector do the following. On the injector body there will be four rows of etched numbers, on the third row down, if the number starts with 8, then you have the updated injector, if it starts with 7, then the next number has to be 8 (78) those were the very first released in late 07, FYI.

 

[weldersd]

YESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



Truck runs perfect:neener:neener:neener

 

[ChevyDMax89]

YESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



Truck runs perfect:neener:neener:neener

Great to hear !!

 

[blacksmokelb7]

Back to burning black gold!!!

 

[weldersd]

Back to burning black gold!!!

You got that right buddy!! thanks everybody who has helped me along with this mess, I learned alot and hopefully this thread can help sombody else,

Note to online worldn LB7 engine, if you get 0202 0203 0205 0208 2149 and can't find any electrical problem, and a resistance test on all injectors is good, the solenoid in an injector can still be bad, I want to know how the tech pinpointed the bad injector???

 

[weldersd]

Just went for a test drive, was running perfect, better than ever, going down a hill in tow mode, big fuel knock, limp mode again, parked it, read codes, now it's the other group, A 0101 0104 0106 0108 2146 injector group A injector circuit voltage open


WTF can this be???

 

[weldersd]

UPDATE:
After hunting down the tech who diagnosed the first bad injector, to told me how he did it, very simple, located the injector with the least amount of resistance to ground after unplugging the harness, I did so and found the following results:

Ohms cyl1=28 cyl3=O/L cyl 5=48 cyl7=114 cyl2=3 cyl4=.9 cyl6=2.9 cyl8=3

So this would suggest if I was to replace just one injector, obviously no. 4 is the shorted injector. The next least resistance injectors would shortly follow. The injector tech at advanced diesel injectors inc. told me in thousands of injectors he’s tested (lb7) mine was the second he’s seen with a dead short in the solenoid. Now it looks all are doomed to the same fate, what is causing this??

I recently got off the phone with an ex bosch engineer @ EXERGY PERFORMANCE Extremely nice and knowledgeable fellows, anyway We went over some possible scenarios of why this is happening, here is some ideas we came up with:

- the fuel injectors have leaks designed into them, they are intended to cool themselves off, with the higher viscosity the fuel might not be flowing fast enough out of the return line, therefore not transferring enough heat causing excessive heat in the injector, thereby melting the plastic housing that protects the injector solenoid.

- The EGT’s are so high the injectors are cooking causing the same problem as above

- The E85 is reacting with the plastic composites causing decomposition of the internal plastic/epoxy components, (Rodgers epoxy, Dupont PEEK) All of which chemicals are known to be 100% compatible with motor oil, atf, and e85 according to the engineer.

Now I’m going to replace all the drivers side valve cover injectors. And just wait I suppose for the next group to go out.

 

[duramxlove03]

Wow. You are a brave man. Best of luck.

 

[Firefighter08]

I read your first post but have to ask, any regrets running the WMO with the problems your having? Will you continue to experiment with fuels after you get her running again?

 

[weldersd]

Wow. You are a brave man. Best of luck.

Thanks, right now i feel beat down.

I read your first post but have to ask, any regrets running the WMO with the problems your having? Will you continue to experiment with fuels after you get her running again?

I'm committed to my alternative fuel source, if If I can't get the duramax to run on it, i'll get rid of her and go to an old model cummins. 50/50 is ok I'm pretty sure I can run that ratio with the dmax, viscosity is key as i'm finding out.

Today I replaced all 4 injectors on the drivers side (most difficult side by far) same code, 0201 0204 0206 0207 2146 tomorrow I replace the three injectors I did not replace monday on the passenger side, why the old injectors are showing continuity to ground is just beyond me, extremely puzzled. tomorrow she will have 8 new injectors, my new filter arrives tomorrow also. i'll let yo know how it goes.

 

[Firefighter08]

Best of luck to you bud, keep us posted!

 

[weldersd]

here's the injector numbers I was talking about, third row from the top, if it starts with 79 or above, it's a "updated" injector, the even Bosch deny's for some reason. And my red neck injector puller.

 

[weldersd]

here is the DMM with one probe connected to engine ground, one connected to injector terminal, continuity, this was after removal, just setting the injector in the hole and testing.

 

[weldersd]

I have accumulated some lb7 parts during this mess, the injectors are cores, but if anybody needs a harness, injector pigtails, or FICM, let me know, cheap cheap. replacing did not fix the problem, so these are known good units.

 

[slo truck]

Just wondering do you think you are still in the "black" as far as cost goes with the current issues with using the WMO/mix. Than if you would have just ran pump diesel. Still think its cool you are being persistent with this. Hell if all else you will be a full blown D-max tech on lb7's

 

[weldersd]

Just wondering do you think you are still in the "black" as far as cost goes with the current issues with using the WMO/mix. Than if you would have just ran pump diesel. Still think its cool you are being persistent with this. Hell if all else you will be a full blown D-max tech on lb7's

I was getting just into the black, then I went WAY in the red again with this ordeal. I estimate on parts I'll spend about 2100.00 I won't even get into my time, alot of hours. I just broke even, so a major set back, I need to definitely determine the cause of the solenoid open circuits before I will try it again the the degree I was running it.

And yes, I already know way more than I wanted to about these motors. That's why I like these forums, while I learn from this, hopefully others can too.

 

[weldersd]

Here is the worst injector so far as far as coke build up. no. 7 injector.

 

[weldersd]

here is no. 1 injector (front) next to no. 7 injector (back) big difference in the amount of fouling.

 

[weldersd]

I could not help myself, it's in my nature to take things apart to try to figure them out, I have always been that way, sometimes it's good, sometimes not.

I looked for a smoking gun, none to be found.

The solenoid is a solid-state type, with no real moving parts, the voltage from the ficm activates the coil to create a strong magnet pulling the pintle out of it's seat thereby injecting the pressurized fuel waiting to be released, at least that's the way I see it. I looked at the pintle taper seat, looked fine, pintle looked good, they just are shorted out to ground for what reason I just don't know, i'm thinking the best theory at this time is heat, too much heat is causing the coil inside the stator slowly make some contact with the outer body, that is just a guess, but it makes the most sense, I wonder if I slightly enlarge the return orifice it would aide in heat transfer, I'm going to talk to exergy about that.

 

[cornfed396]

Good Luck,