1999 Ford Explorer Sport Fuel Pump

[firemarshalmike]

Hey all,

I need some help with my daughter's 1999 Ford Explorer Sport 4.0 SOHC.
Fuel Pump help that is. Read many threads and learned alot but I am missing something. She turns ignition on, hears the PCM click, fuel relay click, fuel pump whirrrr. All is great. A few hours later after it has been sitting at school, she hears all the good sounds except for the whirrr of the fuel pump. Then as if by magic and many attempts at turning the ignition, the fuel pump gets back in the game. Once the car starts it runs absoultely flawless. Battery is good. Maxi fuse is good. PCM Relay, Fuel Pump Relay, PCM Diode all are good. Fuel pressure is outstanding once the fuel pump primes. Intertia switch is good. If the fuel pump is bad, would you be able to drive it without it stalling or acting up? I get it home and let it sit and then go out a couple of hours later turn the ignition on and 10 times out of 12, all is great. I have followed the wiring as close to the tank as I can get and there appear to be no crimping or breaks. It would not start for her the other day, (no fuel pump noise) and her friend jumped the car off and she said it started instantly. Go figure. It seems that it takes a jolt of electricity to get it working again. I am thinking the sending unit but wanted to ask you all what you thought. Thanks for your time.

 

[89newporker]

I'd still suspect the F/P relay if she is rocking the ignition switch back and forth, sounds to me that she's dealing with a sticking relay.

 

[FinksFord]

The extra jolt of electricity working might explain it...IF the relay switch is stuck, that extra jolt might have "unstuck it" ? Trade it out with another switch and see what happens...

 

[drdoom]

I wonder if the fuel pump is having intermittent failures, due to age and/or cleanliness of the fuel tank. The fuel with ethanol can really leave some nasty residue in the tank & pump. Does she use fuel system cleaner regularly? I had some trouble this past summer with the check valve on the pump, and was looking for pumps. I just knew the time was near, and soon I would be dropping the tank. I contacted numerous vendors regarding the terminal size, was mine narrow or wide? I have never seen the pump myself, and even with the VIN I did not know which one to order. Maybe it doesnt even matter. Anyway I never ordered one, but I did start adding mystery oil again on occasion no problems since. Now I'm not saying "put some.mystery oil in that piece, and that will fix her problem". What I'm saying is after thirteen years or so, some cleaning COULD be beneficial. Which brings up fuel system cleaners...there must be hundreds of products to choose from. What I would use is StarTron, run that for a bit. The cleaning is so thorough you will need a fnilter afterwardsSorry for rambling.

 

[firemarshalmike]

Thanks

Hey all,

Thank you for the responses. I have verified that the relays are good. The tank itself is a possibility. I think my PATS system is involved. I understand that all my relays would still click, but the fuel pump won't fire up. Of course we have only one key. I have to research what is involved in putting in a new transceiver.

Finksford----Fink is my last name as well.

 

[hermosatrout]

I have the same car and exactly the same problem. Please advise what was the final outcome.
Thanks