2002 lb7 duramax, stock, just got the truck. just put 8 new injectors, fuel filter,return line seals, used old high pressure lines but cleaned the **** out of them. i thought it needed injectors but after i put new ones in it still runs rough. with my scan tool i can shut off cyl4 doesnt seem to make it run different. it will occasionally hit up on all cylinder for like a second. tested compression cyl2 is 330ish. cyl4 is 210. cyl6 is 265. couldnt do 8 because i had a home made pressure tester . when i shut off cyl6 it seemed to make a difference. there is no whiter smoke coming out of the oil filler neck but the truck still smokes white?

 

Where did you get the new injectors

 

Hopefully not from eBay aftermarket remans.....I feel like I've been down this rd before haha

 

from gm

 

there gunuine gm remans

 

start with getting the balance rates checked and if you have someone with a Tech 2 do it have the command max fuel pressure and post results,

could be weak cp3 fuel pump messed up injector harness or a ecm issue

 

Max fuel pressure can be commanded by unplugging cp3 I'd check the harness

 

Yeah it can but you can't read it without a scanner of some kind and it's a pain in the *** to plug it back in trust me just went threw that finding a leak on the high pressure side

 

When I do injection pumps on these I go pick up my mom and bring her out in garage to pull the bolts out and put them in BC its a pain in *** with big hands make ur old lady unplug the cp3 haha

 

haha i used a long pair of needle noose to unplug and plug it with the engine put together pain in the *** to plug back in......