96 explorer fuel problem sometimes it starts and has fuel at fuel rail--sometimes
no fuel at rail so no start or run--I took fuel filter off and got new one thinking itwas clogged--not problem-- so I have 2 questions--should I be able to blow back thru line at filter towards gas tank with air pressure or not --has anyone ever done this???--2nd question when I cycle key from off position to on position I have 12 volts for about 3 seconds then it goes to about 7 volts is that normal or is that a problem --thanks for any help in advance

 

The 3 sec power on is normal (prime).

The ONLY way to test the fuel system is with a gauge on the rail...... Philip

 

It sounds to me like a fuel pump relay or the pump itself.

 

every time you turn the key "on", the pump runs for 3 seconds to push fuel into the fuel rail for a good start. After shutting off the truck, look for a schrader vavle on the fuel rail un the VEE of the motor. Push the center button and see if you have pressure. Should maintain pressure for quite some time after shut down... maybe 20-30 psi. There is also a pressure regulator by the firewall , probalby by the brake cansiter on the fule rail. It maintains pressure on the fuel rail. If the diaphram failes, you will loose pressure on the schrader valve within 60 seconds after shut down--- buy new regulator. Fule pump might not boost up to 40 spi, but suspect the regulator first and check it.

 

^^^^ Reps sent for a great suggestion.