My turn, second or third shop to play with it. No one has figure it out. Has had recent head gaskets and high pressure pump gasket/harness reseal of inj. Truck will start and run normal all day once I bleed air off high pressure side. Let set overnight starts up and stalls then crank no start like no fuel to high pressure pump. Purge air at cooler through banjo fitting. starts and runs normal. Suspect low side is draining back just not sure what is causing it. Looked through serviced manual it shows 2 check valves 1 in return line at fitting from head returns and 1 in lift pump.I inspection all of banjo fitting All banjo fittings look to have green pain on them. Book does not show any with check valves, I know 6.0 did have some. Is there a good test to check to which drain back is no holding.
