Fuel delivery?

[DKeen]

It appears that I am getting air into my line from somewhere? Truck stalled after restart when parked for 1/2 hour. Opened bleed valve on top of the filter and it took a few min. for fuel to come out. I just replanced the auxiliary fuel filter uder cab and I have bleed the thing a dozen times.

Can these things suck air from somewhere else? ie. small whole in line.

Over the past year I have replaced:
IP, Lift pump, PMD, fuel tank, electronic filter harness ----- but I have added:
aux. filter
turbo master

Any thoughts?

[tom.mcinerney]

DKeen

The symptom you describe 'start, then stall', is a classic indication of Lift Pump failure. On my '95 the usual culprit is burnt points in the OPS (OilPressureSwitch) . On your model the PCM may activate the LP directly, or via relay.
Suggest pressure/volume test , or voltage/current to pump {pumps have been known to fail after only a few months service, both bad fuel and bad electric supply have been implicated}.

Air can screw up the works if it is sucked in. Did you splurge for a new fuel-sender/screen-sock/pickup assembly when renewed the tank?? The screen-sock abrades and passes debris into valve(s) of LP. There is a valve in the fuel pickup tube which bypasses the screen-sock at the bottom ,intended to allow fuel delivery even in conditions such as a clogged screen from diesel waxing/gelling at low temps ; these can stick open a bit on an old rusty pickup, esp after a bad/dirty tank of fuel. [It is thus good to run with tank more than half full to guarantee delivery thru bypassed valve when cold, and to cool PMD when hot].

I think sometimes the fuel lines between tank and engine clog (feed and return) , requiring being blown clear with shop air. If moisture in tank, it's more susceptible to biological agents clogging [better tank kept full, no condensation].

Sometimes the tank filler-cap seals too well, denying the LP a healthy prime, fuel starvation results. Scene: I've pulled into autoparts pkg lot, waiting a minute to shut down before buy oil change supplies. Guy gets in truck 50' away, cranks engine twice. Nothing. Flys out of cab, whips open fuel fill-door, loosens cap, leaps back into cab,(all in a smoothe movement) cranks engine while door shuts, 6.5L roars to life...truck departs!

I'd start with OPS and harness gnd at psgr head rear...but check your year's wiring.