Help: LB7 in need of some wisdom...

Crew cab blue lb7

New member
Aug 4, 2014
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0
0
So I recently purchased what the salesman said was a stock duramax. Lb7 but it had a CAT and an EGR. I will fix those problems later. My main concern is my injectors. He said they had been re-done and they took a dump on me recently. hazing and everything. Smoking at an idle. I am crazy worried. I found some injectors and they are DDP 40% over injectors. Now all my friends tell me my truck isn't stock because it rolls too much coal to be stock. My main question is, will a stock lb7 handle 40% injectors??
 

The Neens

BFD
Staff member
Aug 10, 2006
4,596
1
36
Monrovia, Ca.
What are your goals for the truck?...If you plan on keeping it stock-ish, you'd be better off replacing any bad injectors with stock ones and getting some decent tuning, for starters...
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
If the injectors are going out, high return fuel rates can cause low rail pressure, which can cause excess black smoke.

If you don't plan to tune the truck at all, stick with stock injectors. +40% injectors on the stock tune will probably smoke a lot. Honestly, a tune on stock injectors will run better and safer than bigger injectors on a stock tune.

If you plan to make ~400 HP (or less), stick with stock injectors. If you want more than that down the road, get +60% injectors. Anything less than +50% is kind of a waste, IMO (unless you can get them cheap, obviously).
 

Crew cab blue lb7

New member
Aug 4, 2014
3
0
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Thanks guys. I don't plan on keeping it stock for very long. I plan on putting Air Dog lift pump on it then a 5 stage EFI Live tuning from idaho rob.