LB7 removed Fleece Allilocker, no start now.

Cornell

LBZ for life
Sep 11, 2006
1,601
0
0
Minnesota
First off the truck: LB7, Katie's truck that was built by Wehrli. Compound turbos, etc, etc.


Posting this for a buddy because we spent 3 hours last night in the shop trying to get the truck started, truck drove into the shop fine before he pulled the Fleece allilocker, after removing it truck cranks over and sputters for maybe a second and nothing, white smoke out of the stack.

He removed the Allilocker, the blue/white wires were tapped 6" into the OEM harness, then the Fleece Tapshifter piggyback harness was plugged into that. Ground and keyed orange wire where they needed to be, actually the orange wire was tapped into the 10A ign fuse in the cab. We tried putting the allilocker back in and still wouldn't start. Red plug, pin 29, brown wire on the TCM plug is what the white and blue wires were tapped into.

Could it be something with anti-theft? Security light turns off right away when you turn the truck on. No codes, nothing.

I'm stumped, checked wires, fuses, grounds. It's not like he tore the truck apart to pull the alli locker out.

This truck HATED tow/haul mode when running and always has. The alli locker never was even turned on or used.

I pulled fuse box cover and unclipped it to look at the bottom side, found 2 wires a mouse had nibbled on the wire sheathing but wires were all intact. I don't think that's what caused this. Anyways I taped them back up.

I even got to the point where I was just shaking/jiggling the harness hoping it was something silly while he attempted to start it.



Any suggestions?
 
Last edited:

Cornell

LBZ for life
Sep 11, 2006
1,601
0
0
Minnesota
Have you tried going back to a stock tune? Is VATS disabled in the tune? Rail pressure and all that good?

Rail pressure was fine, I'd have to check with Katie about a stock tune.

Didn't try the Vats relearn and don't know if it was turned off in the tune, neither the 10 minute nor 30 minute procedure were done however

Not sure about LB7's been so long since I had mine but could the internal TCM ground be fried? I know I fried mine on my LBZ being lazy and needed a new one. In the mean time I just soldered an external ground to my LBZ TCM until the new one showed up and I put the cover over it GM didn't.

Truck cranks though, my LBZ didn't when the ground was gone.
 

Cornell

LBZ for life
Sep 11, 2006
1,601
0
0
Minnesota
All piggy back wires that were exposed none are touching anywhere right? Everything taped up?

Yeah everything was taped up and brown wire was spliced back together.

If its not something with the allilocker its just a huge coincidence it popped up now.
 

Robby Avery

GM TECH @ FENDER GMC
Jul 31, 2008
820
2
18
Norman Park, Georgia
Hearing the pump and seeing a number are totally different no flow no go motor can spin and vane in the housing could be still due to separation from motor shaft no gauge I presume for pressure reading?
 

Cornell

LBZ for life
Sep 11, 2006
1,601
0
0
Minnesota
Hearing the pump and seeing a number are totally different no flow no go motor can spin and vane in the housing could be still due to separation from motor shaft no gauge I presume for pressure reading?

Fuel no, rail pressure yes.

Might suggest bleeding system tomorrow I have to talk with Ike and Katie.
 

Robby Avery

GM TECH @ FENDER GMC
Jul 31, 2008
820
2
18
Norman Park, Georgia
Gotcha mention that a fuel pressure gauge is a good idea for situations like this it will be a taddle tail gauge if the liftpump has a no flow problem ask them to pull line loose if filter housing has been deleted and briefly turn key on to see if any fuel is even being moved again no flow no go you know :thumb:
 

Cornell

LBZ for life
Sep 11, 2006
1,601
0
0
Minnesota
Gotcha mention that a fuel pressure gauge is a good idea for situations like this it will be a taddle tail gauge if the liftpump has a no flow problem ask them to pull line loose if filter housing has been deleted and briefly turn key on to see if any fuel is even being moved again no flow no go you know :thumb:

Yes, in a situation like this it would be very helpful.:roflmao: Not my truck just trying to find a solution we hadn't thought of yet
 

Lb7_Katie

Lb7 Duramax
Sep 8, 2013
851
31
28
34
Gotcha mention that a fuel pressure gauge is a good idea for situations like this it will be a taddle tail gauge if the liftpump has a no flow problem ask them to pull line loose if filter housing has been deleted and briefly turn key on to see if any fuel is even being moved again no flow no go you know :thumb:



Yes, in a situation like this it would be very helpful.:roflmao: Not my truck just trying to find a solution we hadn't thought of yet


Thanks! I appreciate all the help! Ike's gonna check all the fuel lines and I'll have him check the air dog make sure there's no air in the lines or anything. As well as speak with Nick again let him know the new codes the truck threw. Since those codes weren't there when it was logged and see what he wants me to do with it.

Once again I appreciate all the help!


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