1987 Ranger losing prime fuel pump ??

[raggedyann]

1987 Ranger losing prime fuel pump
stx 2.9 I must cycle key on/off several times before it will start. like its losing prime. it does this hot or cold.
would the fault be a bad pump check valve ? it has the frame mounted pump and the in-tank pump.
no fuel at FPR vacuum line.
any tests to tell which pump is faulty ??

 

[RonD]

Assuming engine is not running rich from stuck open injector I would test this way:
Cold engine
Remove return fuel line from FPR, put a towel down in case it is leaking
Turn key on/off several times, as said Prime the system
If fuel comes out of FPR replace it, it should be closed and holding the pressure with engine off and no vacuum.

If no fuel comes out, then yes, check valve in fuel pump is the issue.
1987 should have it's high pressure fuel pump in the frame rail, the check valve would be part of that pump.

 

[Earl43P]

I'd go one step further.
Disconnect the OUT line of the fuel filter.
Disconnect the electrical connector on the framerail High Pressure pump.
Cycle key on 3 sec / Off / repeat and see that the lift pump in the tank is supplying good fuel flow.
Reconnect framerail pump, repeat key cycles and look for a LOT more flow.

Need I say use a section of tubing and a bucket....