DieselWife

I'm new! So far the community is awesome.. this might be long. First Diesel for us.. We baught it used with 155,000 miles.. It's a 2008, 2500 6.7. Only had it for a month and for a week it ran fine. . We knew the 4x4 needed work.

So to start we baught a used 4x4 acuator motor. It was a simple fix (or so we thaught) that part ended up being bad. So took it back and baught a rebuilt one from orilly, and a dash switch.. 4x4 fixed. So once we put the used one in. The truck started dying for no reason.. thinking it was from the used 4x4 acuator, replacing with a new one would fix it.. wrong.. so we changed the fuel filter. Still dying.. but now we have noticed a pattern.. When first started it will run perfect.. as long as you want. . As far.. no problems.. once it's warm and you shut it off.. when restarted, it will run about 5 min or less then die, engine totally cut out..then it won't restart.. if it does run its a second or 2 and redies. It started throwing the lightning bolt code.. reading it could be loosing battery power.. we replaced the 2 batteries.. codes come and go.. so it's weird.. still no fix.. still consistent with dying after driven, warmed, and restarted...Had a detailed code print out from Auto zone.. (while they was on, they go off after a few starts). Said it was something to do with fuel pump and low pressure, high pressure. So ordered the part and parked it till we got it replaced ( the one in the gas tank).. Still no fix.. consistent on dieing after ran, warmed, turned off then restarted. Now what?

And apart from that. . While testing the 4x4 after fixed, it got stuck in 4x4.. finally switched to 2wd then while driving put itself back into 4x4 at 40mph .. when turned off and restarted it was back into 2wd... maybe something to do with whatever is going on or a whole new problem?

Sorry for typos. On my phone . We are not willing to give up.. We love the truck! Just running out of options.. feel like we are chasing a ghost.. oh I should mention that when the "used" 4x4 actuator motor was replaced and didn't work a few fuses were pulled and checked bY a buddy that was helping.. that's when it started the dieing.

BigIron70

What codes did they pull? would be helpful.

DieselWife

Error Code Reading
PO628 Fuel Pump Control Circuit Low
PO629 Fuel Pump Control Circuit High
PO087 Fuel Rail/System Pressure -Too Low

Definition
Code PO628 indicates that the Fuel Pump Control electrical circuit signal hall low voltage for a predetermined period of time.

This was what the Auto zone printout said. Yesterday after the fuel pump (lift pump) was replaced and it died after running, warming, and restarting the lightning bolt came on again. . And threw codes (with the key turn 3 times reading) P0513 and P0087.. but went away with no codes once we got home.

DieselWife

Maybe I put this in the wrong place. .

xcc_rider

It's in the right place. I just don't have the service manual on this tablet.
It sounds like you're chasing a short or bad connection to the fuel pump. I'll dig out my old tablet and post up the code diagnostics for the fuel pump code as soon as I can.

dodgebre3500

Hey check the electric connection at fuel filter bowel,the clip on mine broke so it would not stay connected. and when lightin bolt comes on does;nt that mean water in fuel, but any ways check that connection

xcc_rider

I looked at the diagnostics and there's some drawings that won't copy so I think you'd be better off downloading the manual and looking the codes up yourself (besides its a great resource). Go here: CarboniteCummins - Articles for the manual.
If you have problems downloading it you can go here: https://www.dropbox.com/s/179nplllhk...iesel.pdf?dl=0 and download just the diagnostics section.

Both codes 0628 & 629 list a wiring short as a cause and since you just got done working on the truck I'd suggest you check all the wiring looms in the proximity of where you were working and see if any are damaged. Especially any to/from the film and fuel pump.

BigIron70

I would have checked power and grounds at the fuel pump module first. I have seen poor ground connections cause this issue in the past. Fuel pump is grounded at the frame rail left side wheel well area. Check for corrosion or loose grounds.
here is diagnostic tests if code is still setting.