Help: LBZ randomly Shutting down

[aggar]

Ok here's the story.
January I swapped motors in my LBZ. Left off the dual pumps. It ran good no problems. BUt one time at home the truck started then died immediately. Started again adn died. Started third time and held foot on throttle and stayed running. Ran around and it was fine. Went to start a couple days later and batteries were weak. Replaced batteries and everything was fine. Batteries were replaced in Feb. 2 weeks ago I had it detuned for a more streetable truck. Well On sunday I was driving around with wife and daughter and stopped at a stop sign and truck shut down and dash said not charging. Started right back up and amps were around 14. Pulled into Pep boys to check it out and see if they might have an alternator. No luck in town. Figured I could make the errands and home. well Stopped at another light and it died again. Started right back up.

Put new alternator on yesterday and started fine and rans 2 minutes and died. Started right back up and ran a couple more minutes and died. On the second time when it died it knocked a little bit. Sarted it up today and it ran for about 2 minutes and made a couple knocks but stayed running. Drove around town for some errands and back to the shop and I stopped and was letting the pyro cool and then it died.

Everytime it has died, No codes. I've checked the grounds, disconnected the batteries and reconnected. Checked grounds on block and any I can find. I'm Puzzeled. Any ideas on diagnosing?

thanks.

Ryan

 

[JoshH]

Reluctor wheel problem? Just a guess.

 

[aggar]

Where would that be? Nothing on the gauges shows anything unordinary.

 

[aggar]

I'm listening to it idle outside and it just knocked a couple times and almost died but stayed running. Any ideas?

 

[JoshH]

The only thing I can think of that would make it knock would be a fuel issue, be it timing or pressure or a combination of the two. If it was a relcutor wheel problem, that would make the timing jump around, and it may or may not show on a log. The pressure could be affected by a bad rail pressure sensor, but that would almost certainly show on a log. I seem to remember someone having a problem with a recently built motor running for a while, and then it would no longer start. Turned out he had the cam and crank position sensor connectors crossed. Anyway, I would check to make sure the sensors are plugged into the correct plug, make sure they are fully seated in the front cover, and maybe pull the crank sensor to make sure the wheel is tight on the gear.

 

[aggar]

I'll look into that but This motor i swapped was not taken apart. It ran fine for 2 months and then i got it retuned and after that it started acting up. Thinking it may be my tuner's laptop.

 

[maxaholic]

Check the red junction block. Mine said battery not charging and that nut was not tight. Tightened it up and all is well.

 

[LBZ]

Maybe check injector connections as well. Bale connectors and all of the grounds as well.

 

[aggar]

Bumping it up. I'm gonna check all those connections but there's another thread on here abot the same thing. Mine doesn't die while moving it's just when sitting idle.

 

[aggar]

ok new symptom. While driving it now will try to die but spits and sputters then runs fine. Died at a light and almost didnt start back up. Now after the episodes it says my oil life is 0%. Even though i just put new oil in. My ground wires on the block are a little curroded(sp) in the copper where it was crimped onto the end. I'm gonna replace those grounds from the batteries to the block and maybe that will be it. Am I on the right track??

 

[dmaxfireman]

junction block or bail connections / ecm is where i would be focusing

 

[LBZ_Duramax]

As far as the oil life did you reset it when you changed the oil?

 

[LBZ]

Have you tried reflashing the ECM?
I had this happen a couple times. Flashed a tune, drove for 5 min and then it died. Wouldn't restart. Gauges went all retarded as well.
Flashed a different tune in and it worked so I don't know if it was just a bad tune or if something happened when I flashed it. I didn't retry the tune to confirm though....

Not sure if this is your issue or not.

 

[aggar]

I'm thinking this might be. I need to try it this evening.

 

[aggar]

Well I messed with the airdog yesterday and since I've done that it hasn't done anything. But After that also I returned it to stock tuning. Seems to be ok so far. I'm gonna try it stock for a couple days and see how it does then put a tune it later.