The Ford Explorer is a mid-size, four-door sport utility vehicle that debuted in North America in the 1991 model year. The Explorer underwent a design overhaul in 2006 with a new frame configuration, redesigned rear suspension, an added tire pressure monitoring system, electronic stability control and a new interior with power-folding third-row seats.
Check the fuel delivery system in the Ford Explorer if the engine is running rough, hesitating, stalling out while driving or not starting at all.
Relieve fuel system pressure. Disconnect the negative battery cable and remove the door frame scuff plate from the front passenger door frame, which includes removing the internal metal retaining clips. Disconnect the Inertia Fuel Shutoff (IFS) switch electrical connector and start the Explorer. Let it run until it stalls out. Crank the engine for at least five seconds after it stalls to relieve all system pressure. Turn the ignition off.
Disconnect the fuel pressure sensor vacuum hose and check for fuel in the line. Refer to the owner's manual for the line's location if you aren't sure which one it is. If there is fuel present in the line, the fuel delivery problem is likely caused by a faulty fuel pump pressure regulator, which means there is not enough fuel in the engine for proper function. If there is no fuel in the lines, reattach the vacuum hose and continue with the fuel delivery diagnostic.
Remove the cap from the fuel pressure relief valve and attach a fuel pressure test gauge. Reconnect the negative battery cable and turn the ignition key to the first position. Do not start the engine. Check the pressure gauge. It needs to read between 39 and 42 pounds per square inch. Pressure that's too high is another indicator that the pressure regulator is malfunctioning. Pressure that's too low indicates that the fuel filter is clogged or that the fuel pump needs to be replaced.
Turn the ignition off, remove the pressure gauge and the negative battery cable again so you can safely remove the fuel filter to check for clogs. Raise the Ford Explorer, unscrew the bolts from the fuel filter heat shield and remove the shield. Remove the nuts and then the fuel filter shield.
Disengage the quick release and spring lock couplings and extract the fuel filter. Visually check the filter for clogs and replace it with a new one if necessary. If there are no clogs, the fuel delivery problem is probably caused by a faulty fuel pump. Install or reinstall the fuel filter by reversing the removal steps from Steps 5 and 6. Tighten the bolts on the fuel filter heat shield to 15 foot pounds (20 Nm.)
Lower the Explorer, reconnect the negative battery cable and start the engine. Visually check for any leaking fuel.
