12.7 questions

Ill bet you simply lost prime. I had that problem after changing an injector. I rigged a portable air compressor up by cutting the end off of hose, clamping it onto tank vent, crimped off other vent line. And plugged it into cigarette lighter. It took a while, but about 10 lbs is all that’s needed to push fuel up into system. Afterwards unhook air compressor and let air bleed out. Don’t try to take cap off, A little pressure goes a long way, almost broke my hand, Lol

 

I would run a hot wire from the batteries to the neg and POS side of the ECM with some good clean cables to rule out that connection being bad.

 

The newer 14 L have a fitting to pressurize fuel system, but as far as I know the 12.7 doesn’t. They claim a lot of cranking will restore prime, I tried 5 hrs with jumper cables, wonder I didn’t burn up starter. I over did it with 20 lbs of pressure. Truck started then shut off. Bled off excess air, and one little shot of ether it fired up.

 

No no no you’ll burn it up possibly

 

How ?

 

I dont know, don’t want to find out. Power to ecm has a 5 amp fuse, Lights on dash confirm power.I don’t really know much about ecm, except that they’re expensive.

 

I’m guessing that fuel pump went bad, and now he’s lost prime from tanks, after changing pump.

 

I think it should be cranking a lot of fuel from the pump. Try disconnecting the first hose from pump at the filter, see how much fuel it cranks out, it should be a lot.Ill bet it’s not putting out anymore than at back of head, because it’s lost it’s prime. Only way I know of, short of cranking forever ( so they say) is to pressurize fuel tanks.