1988, 5.0, A/T, 2WD

Progression of symptoms:
- Would run rough/miss for the first few minutes until warm
- Slight detonation under load

Now:
- Will not start in any condition (may half-start, but will stumble badly and stall out quickly)
- Fuel pressure around 10 psi at fuel rail schrader valve
- Will start smoothly with starter fluid, but will not continue to run

What's the best way to appraoch this from a troubleshooting standpoint? Fuel filter, then FPR, then external fuel pump? I hear the pump running when the key in on, and obviously I'm getting some pressure? Ideas?

Thanks!
Mike

 

You say you hear the high pressure pump running.
So it would be the selector switch, fuel filter, bad in-tank pumps or the fuel selector valve.
Is the fuel pump running all the time the key is on?

Start by grounding pin #6 of the EEC self-test connector and then turn on the key.
This will allow the fuel pumps to run and not time out after one second.
Select each tank one at a time and listen each time at the fuel cap and see if you hear the pump run.

The EEC self-test connector:
http://i54.photobucket.com/albums/g9...onnectorFP.jpg

/