99 Sport - Fuel Pump Question - Can reproduce

[Motolz]

So I have a wonderful 99 Explorer Sport that never quits.. until now... I have a 'crank wont start' issue that I can pin point an issue, but need an answer.
1) I swapped the relays... still won't start.
2) After sitting over night, I pushed the Fuel Pump schrader valve and nothing came out
3) I turned the key and depressed the valve and I do have pressure.
4) I tried to start and it started right up!
5) Turned off and restarted several times.. no problem
6) let sit for 30 minutes.... would not start..crank no start
7) key on..pressed the schrader valve... I have pressure
8) tried to start..started right up!!

So bottom line, If I 'prime' the line' by depressing the valve with the key on, it starts. Seems like some kind of vacuum issue or something. Anyone experience this and resolve?

Thanks all! 200k and still running... well mostly!

Motolz

 

[MrQ]

You really need to check your fuel pressure before going much farther. You need to have above 60 psi. Anything less and you have a fuel issue. It is not uncommon for the fuel to drain back out of the line overnight, but not within 30 minutes. The fuel pressure tester will tell you how fast you are losing pressure with the pump off.

Your method of priming is a little different than most. Usually to prime the system you cycle the key off and on to run 2 or 3 times to build pressure.