Diesel fuel filling #3 after injector replacement please help!

[Boatracer69r]

I didn't know where to put this post so if you need to move it to the appropriate place I would appreciate it. I'm new to diesels and don't know a lot about them. I've always been a gas engine guy so bare with me while I try to explain what is going on with my truck.

I recently just replaced all eight injectors on my 2002 GMC with reman Bosch injectors. After getting it put all back together the computer threw a code saying #3 was misfiring. We took it back down and replaced the # 3 injector with another Bosch injector. After putting it all back together again, it did the same thing. We then discovered diesel fuel is filling up number 3 cylinder and we cant figure out why. Could it the ficm, a leaking return fuel line, wiring harness? We are at a loss as to what it could be. Any help on this would be greatly appreciated. Thank you.

 

[Slowmax]

Have you or did you perform a compression check yet?

 

[Boatracer69r]

Yes we did a compression check and everything checked out great. I dont have the numbers in front of me, but my friend who is helping me (he has the shop and area/tools to do all this) said he did the compression check and everything was great. He is at a loss as well, that is why I am reaching out to people. He said that he did a powerstroke and had to replace the ficm.

 

[dirtydmax]

Codes?could have a shorted injector harness.dont ask how I know that one

 

[Dmax87]

Not quite sure how diesel is filling up the cylinder. Sure you have all harnesses in correct locations and plugged in correctly? Are you saying #3 is just stuck wide open or??????

 

[baddaddition]

Id say ya might have either dirty fuel line of continue to get dirt in it where it is hanging open maybe... Just a thought. Lb7s are temperamental little B*****s. You sure you got the wires on correctly? Reds to the fro t yellows to the rear and red with red yellow with yellow.?

Sent from my XT1254 using Tapatalk

 

[catman3126]

so it has to be smoking a ton if its filling that cylinder with fuel? is it white smoke? what happens if you disconnect the wires from that cylinder? does it continue or just have a miss? yeah you can unplug the two cylinders and run it on 6 cylinders and see what it does. Did you replace the HP lines to the injectors or at least clean them really well? x2 on the rust contamination from the HP line. if not replaced or cleaned at the least you could be dropping rust right in the new injector.

 

[catman3126]

I didn't know where to put this post so if you need to move it to the appropriate place I would appreciate it. I'm new to diesels and don't know a lot about them. I've always been a gas engine guy so bare with me while I try to explain what is going on with my truck.

I recently just replaced all eight injectors on my 2002 GMC with reman Bosch injectors. After getting it put all back together the computer threw a code saying #3 was misfiring. We took it back down and replaced the # 3 injector with another Bosch injector. After putting it all back together again, it did the same thing. We then discovered diesel fuel is filling up number 3 cylinder and we cant figure out why. Could it the ficm, a leaking return fuel line, wiring harness? We are at a loss as to what it could be. Any help on this would be greatly appreciated. Thank you.

LOL its a long shot but are you sure you did the right one? did you mix up which one is #3 2nd one back on the passenger side?

 

[catman3126]

what was the original reason for replacing injectors? was it this issue or something else? smoking at idle? knocking from fuel knock?

 

[juddski88]

In addition to Catman's questions, I will say that if the little shim is not installed in the injector nozzle, it will cause this issue. I have received one reman lbz injector this way before.

 

[Boatracer69r]

Sorry the for the delayed response to y'alls questions, but the reason for replacing the injectors was because at idle there was a large amount of white smoke and I got pulled over and given a "last chance" warning to get it fixed or hit with a huge ticket.

The gentleman that is fixing it is a family friend who owns a garage. He has done injectors on numerous duramaxs' and has never had any issues. He did say that my injectors were the worst hes ever seen and couldn't believe it was still running as good as it was. When he took the old injectors out they cleaned the lines out to make sure there wasn't any dirt in the lines. They've hooked it up to the computer and double checked every wire connection to make sure everything is OK, and even took the tuner off my truck back to stock to try and get it to work. He has been absolutely amazing in trying to find this problem as I can guarantee any other shop what just cut it loose and give up. He is coming to a loss so I am just trying to help in anyway I can to fix it by reaching out to y'all the compression was also great so the only thing I can think of is possibly the ficm. Y'all have been great in information so far so any other advise would be greatly appreciated! If you have any questions please let me know and I will do my best to answer, I am mechanically sound but diesel stupid.

 

[Boatracer69r]

Bump

 

[catman3126]

What was the compression reading? what PSI? what in the way of performance have you been running on this truck? tuning? turbo stuff like that?

 

[1ATony]

Thanks for joining, it's great to have you here

Tony :rockon: