Dead LB7

Kunz111

Member
Jan 16, 2016
113
2
18
Hey there everyone, a friend of mine called me up the other day saying that his truck died on him. So I asked him what was going on with it. He said at first the truck would run rough and have a poof if white smoke coming out the exhaust, only at idle though. He said it didn’t feel down on power either. The kept driving it to try and get home and when he came up to a round about it started to run rough all the tire and white smoke all the time. Pulled into a parking lot, shut it off and that was that. So I grabbed my truck and deck over to tow him to my house and when I got there I cranked it over just to see what would happen. It has a nice strong cranking rhythm and after a little bit of cranking the truck would spit and spudder and almost start, it would knock bad a couple of times and then nothing. The entire time I’m cranking it would smoke white out the exhaust, I also looked at the crank pulley to see if it wobbled a lot indicated a broken crank but seems to be ok (not saying that the crank didn’t break in another spot) I towed the truck home and today I had a couple of minutes to go access codes with my autel scanner. No codes. I’m thinking it’s an injector issue but don’t know really how to diagnose those with out the truck running. Any help would be great, I have a lot of experience with Duramax’s, just my first time with a lb7. It’s a 2002 ppe box tuner, lift pump, exhaust, and intake. Injectors have been replaced once before don’t know the mileage though. Currently has 248k.
 

2004LB7

Well-known member
Dec 15, 2010
6,363
1,732
113
Norcal
2x on the hung open injector. You may be able to find it if you pull all of the glow plugs and FCIM fuse. Then crank it over to see if any fuel comes out of the glow plug holes
 

Kunz111

Member
Jan 16, 2016
113
2
18
2x on the hung open injector. You may be able to find it if you pull all of the glow plugs and FCIM fuse. Then crank it over to see if any fuel comes out of the glow plug holes

Thats a good idea. I’ll give that a shot when I get some free time. Thank you.