LBZ strange issue-any ideas or insight is appreciated

[carter_44]

First off, I have now owned over 30 Duramax powered trucks. Yes, three zero...and I have never come across this issue with any generation truck and it is pissing me off a great deal.

Truck is an 07 LBZ SCLB 2wd work truck. Only mods are 4" pipe and Tony's tunes. I was in the middle of a mild build on this truck and this issue arose and has me stumped.

Truck will start perfectly and idle without issue. If I baby the truck it will act as it should and will go through the gears just fine. If you get into the throttle at all it will throw codes and start cutting out/missing. Codes set are p0203, p0208, p2155...sometimes I'll just get one of the three sometimes all of them. I can clear the codes and it will be back to normal until you try to get on it again. Once it throws the code I get a loss of power, rough idle (enough so that the whole truck will shake), and black smoke.

I figured with the injector circuit codes thrown that it must be an electrical issue (wire grounding out or a bad connection). I have checked everything I can think of and cannot find an issue.

This is driving me nuts. Any help or insight is appreciated. I have searched everywhere and cannot find any similar occurrences.

Thanks in advance gentlemen.

Attached is a pic of the truck...it will either be a race truck or I'm going to burn this MF'er to the ground depending on if I can get this thing figured out.

 

[Hot COCOAL]

Dang man, that's your work truck

Can I have a job :hug:
:roflmao:

Looks like a pretty cool truck:thumb:

Have you gone COMPLETELY through all the wiring harness, is it possible it's just a chaffed wire somewhere?

That's Bogus man, you'll get it figured out keep ya head up
and sell it to me before you burn it to the ground:joker:

 

[Chevy1925]

just sell it and move on to dmax number 31 :rofl:

if you have checked all the injector connections and wiring, swap in a known good LBZ ecm and see if it quits

 

[carter_44]

Dang man, that's your work truck

Can I have a job :hug:
:roflmao:

Looks like a pretty cool truck:thumb:

Have you gone COMPLETELY through all the wiring harness, is it possible it's just a chaffed wire somewhere?

That's Bogus man, you'll get it figured out keep ya head up
and sell it to me before you burn it to the ground:joker:

Yeah, I went through the entire harness and insulated every piece of exposed wire.
Work is always hiring. Want to run trains for a living? Haha.
Make me an offer...I may part with it.

just sell it and move on to dmax number 31 :rofl:

if you have checked all the injector connections and wiring, swap in a known good LBZ ecm and see if it quits

James, I'll see if I can talk Kyle out of his ECM to borrow for a minute. It ran fine before the ECM swap and ran fine after swapping in Tony's tuned ECM. The tuned ECM has been in the truck for almost a month and this issue just arose recently. Worth checking but I doubt that is the issue unless I managed to foul that ECM just in the last couple days.

 

[Chevy1925]

doesnt mean they never go bad. shit happens but like i say, if you have really gone over than wiring harness, swapping ecms would be my next choice as you dont have a FICM like the lb7, lly's. its all driven from the ECM

 

[carter_44]

Do you ever actually work?

 

[Chevy1925]

when we aint slow. things die and then i just wait for issues to arise. its more than riding on trains all day reading diesel power

 

[carter_44]

False on all counts:roflmao: