Does the fuel pump need replaced

[ward1102]

Have a 96 explorer over 150 k miles has been running fine. This weekend I made a stop for 10 minutes and when I came out to leave the truck would not start. I was told the fuel pump went out. Then serveral hours later I tried again and it started! So then I was told it was vapor lock. I was told the fuel pump still needs replaced bacause it shut down once. I don't have the extra cash to spend if I don't have to but I don't want to get stuck 20 miles from home either. Being female I'm a little leary about being told one thing then another.....HELP. Does the fuel pump really need replaced? Is it possible for it to go out one day and be fine the next? How does the pump work??
thanks for any advise you can give.
D

[shorod]

Yes, it does sound like a fuel pump. The fuel pump is a DC motor mounted in the fuel tank. It, like any DC motor, will fail over time. Common symptoms of a failing fuel pump are they may start to make more noise (audible whine), or they may cause no start conditions after they've been running a long time, particularly when the fuel tank is at 1/4 full or less. The pump is submerged in fuel normally which helps keep the pump cool. As the fuel level drops, the pump has less fuel surrounding it to help cool it. After it sits for awhile though, it cools enough and will continue working again.

Ever had a starter motor that would not work on really hot days or after long drives, but worked great when the weather was mild? Same concept here.

You could have the fuel pressure checked, both KOER and KOEO. If the pressures are below specification, that further points toward the fuel pump.

-Rod