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Lb7 smokes at idle

Jimmykemp12

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I have a 2003 Chevy 2500 with a 6.6 lb7 it’s blowing smoke out at idle smells like raw diesel the guy I got it from said head gaskets not sure it has bigger injectors not sure what size and no tuner all I found on the smoke is hazing
 

THEFERMANATOR

FRANKENBURBAN
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If it has stock tuning with bigger injectors, that could be your problem. Or it could be they slapped bigger nozzles on worn out stock injector bodies making more expensive bad parts. You need to find out about the tuning, is it using coolant, and some basic history on the truck.
 

DieselSlug

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Like said above you really need to obtain the history on this rig to help properly diagnose. Is there a CEL on? Does the PO have any receipts to validate his allegations?

Need to determine if its aftermarket/performance parts (potentially not combined correctly with tunes) vs. stock worn out parts as well.
 

Rockabillyrat

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99% of the time a LB7 that smokes at idle is injectors. They use a VOC nozzle that are notorious for leaking. Get a scanner on it and cancel injectors one at a time and see if the smoke clears up. Balance rates can help narrow it down too.

But big oversized injectors can do the same thing. I dont see hazing with 30% overs. But if someone put something like 200% overs in it that's might be your issue.
 
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FRANKENBURBAN
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99% of the time a LB7 that smokes at idle is injectors. They use a VOC nozzle that are notorious for leaking. Get a scanner on it and cancel injectors one at a time and see if the smoke clears up. Balance rates can help narrow it down too.

But big oversized injectors can do the same thing. I dont see hazing with 30% overs. But if someone put something like 200% overs in it that's might be your issue.
I've seen 45 overs haze at idle. My 45 over SAC's hazed until I redid my tuning. The big problem with nozzle swaps is most of the time it's a complete waste of money since the ball seat is normally worn in the body. Swapping new nozzles onto worn bodies gives you more expensive junk.
 
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