Hi all,

New poster here looking for help with a 99 Explorer Sport 4wd with about 100k on the clock.

The truck won't start on the first crank. The starter motor is fine and it's getting plenty of spark, but no gas. When you turn the key from off to just before crank you can hear the fuel pump turn on, run for a second and turn off. If you do this 3 times or so the truck will start. It SEEMs as if the pump is having to pressurize the fuel system.

In the last few days though, the pump doesn't always come on when turning the key from off to on. Not sure if this is new or has always been the case.

This problem has gotten progressively worse over the course of 6 months or more and now always requires multiple key on/off cycles for the pump to prime the fuel delivery system.

Thanks in advance for your help!

 

From what you describe it sounds like the fuel pump isn't getting the fuel up to the fuel rail right away. AMONG THE POSSIBILITIES;
1. There is a check valve in the fuel line from the intank pump to the fuel rail , it may not be working properly.

2. There is a fuel pump relay that could be getting "tired".

3. Before condenming the fuel pump itself, Does the vehicle run alright after it gets running?

4. It is necessary to verify all connections to the fuel pump are good and will allow the fuel pump to work properly.

5, Did you check out the fuel filter ?

Will be waiting for your reply, hank

 

Vehicle runs perfectly after starting. When it's having trouble starting, it sometimes stalls before the pump fully primes everything.

My first change will be the fuel filter. It hasn't been replaced in a long time I'm sure.

Where is the check valve located and how would I verify it's working properly?

Thanks tons for your reply!

 

Unfortunately, the check valve is in the fuel pump assy in the gas tank. You can buy and replace the fuel pump with an aftermarket pump, but the rest of the assembly is a dealer item which comes with the pump and o ring . These assemblys run in the area of $300 to $500. Before I would consider replacing the entire unit for that kind of money and the work involved, this is what I would do.
Remove the fuel supply line from the fuel tank before it gets to the pressure regulator. Attach a piece of rubber hose to the tubing and see if you can blow straight thru to the fuel tank . If you can, the check valve is allowing the fuel to drain back into the tank. Keep in mind that you will be blowing through the fuel filter, and it should resist the pressure if the valve is working. Otherwise, it means dropping the fuel tank, disconnecting the fuel lines of which there are 3, Supply, return and vent . It is not a job for the inexperienced since you would want to have the tank as low in fuel as possible because with fuel in it ,it is heavy. If you decide to tackle the job, use a flashlight when working under the vehicle because gasoline leaks out the connections when opened and there is an extreme fire hazard when a droplite is used. This is not the kind of suggestion anyone likes to hear ,but get an estimate from a dealer and an independent shop before you decide to have it replaced. Smart move would also be to get a second opinion. hanky

 

Got ya, and great advice. I'll post back when I change the fuel filter.

 

I forgot one important thing. Don't forget to trip and reset the inertia switch. It is in the circuit for the fuel pump. Sometimes they don't always make the perfect connection. May not do anything, but must touch all the bases. To trip it just give it a good rap with your hand and you will hear the ball roll when it trips. If you are not sure where it is , let me know.

Sorry about that! hanky