LB7: Rattling black smoke and skipping

[JustinD]

I was plowing snow last storm and my truck started to rattle and skip, sounds like a dead hole? EFI won't read the balance rates says all zero?? GM TECHII says all zero too? Took the glow plugs out one at a time and looked to see if one was soaked with fuel but they all look good? Any ideas?

 

[Sledhead]

Can you a get rail pressure reading? Other engine and fuel data to verify comm?

 

[JustinD]

Yes rail pressure is 5700-5800 idling

 

[slipclutchms]

someone one else was having problems reading balance rates and they were all 0. Try re-flashing to stock if you have not already.....then maybe go back to build 133 instead of 139?


Dylan

 

[slipclutchms]

also try re-validating the parameters......I have had that problem before. Try that first actually....

 

[JustinD]

The Tech 2 won't read them either?

 

[tonydduramax]

someone one else was having problems reading balance rates and they were all 0. Try re-flashing to stock if you have not already.....then maybe go back to build 133 instead of 139?


Dylan

x2

 

[DIESELMAFIAPER.LB7]

thats very strange have you checked wiring everwhere?

 

[Righteyeblind]

I know Efi wont read balance rates on my truck unless the idle is at 600 or less. I thought that was kind of wierd but a thought anyways.

 

[SHOTZY]

Is it throwing any codes? I'm guessing its an injector wire under the valve cover. My buddies lb7 did this. Balance rates all read 0 and sounded like a tractor lol. Good luck.

 

[JustinD]

UPDATE:

I went to the shop on lunch break, EFI wouldn't let me turn injectors off one at a time??? So I grabbed the Tech 2 and fumbled my way through it and found the fuel menu I was able to turn each injector off when I got to #3 it smoothed right out, ordered an injector hopefully its the issue??

Back in the summer when I had fuel leak issues under the covers I read balance rates and 3 was off from the others, all the rest were .090 or .080, #3 was like 3.78?? So I'm hoping it just went bad over time?? I will post when it is done and running good hopefully!! I have more snow to plow!!! :rofl:

 

[DIESELMAFIAPER.LB7]

I know Efi wont read balance rates on my truck unless the idle is at 600 or less. I thought that was kind of wierd but a thought anyways.

you should be able to read balance rates all the way to 900 rpm idle useing the dvt function in the scan tool

 

[Righteyeblind]

you should be able to read balance rates all the way to 900 rpm idle useing the dvt function in the scan tool

That's what I thought too but my truck is wierd I guess

 

[JustinD]

Put one injector in it Saturday, seems ok. Runs good and starts alot easier in the morning now. :thumb:

 

[duramaxdiesel]

Glad to hear! Hopefully you're good to go for a while yet:thumb:

Nick

 

[Bonestock]

Efi

I have seen this before and all I had to do was pull the shifter into neutral instead of park. Then the balance rates would display. Hope this helps for future.

 

[JustinD]

I have seen this before and all I had to do was pull the shifter into neutral instead of park. Then the balance rates would display. Hope this helps for future.

Thanks, I'll keep that in mind.