96 Explorer Sport problem, is it my fuel pump?

[Reservetwo38]

This is my first post to the website, I have found great advice here and want to say thanks and post my first query!

So I walked to my 96 Ford Explorer Sport the other day at work and turned the key to idle... no hum from fuel pump and truck would begin to start but wouldnt turn over. My boss calls his mechanic brother and he tells him that having someone turn the key while someone else bangs on the bottom of the fuel tank will sometimes jumpstart the dead fuel pump. We tried this and it worked.

Now the problem is sometimes it starts and sometimes it doesnt, but the majority of the time if I turn the key to idle and give the pump time to hum for about 5 seconds it will always start. But if I turn the key quickly past idle to start the engine the pump wont hum and doesnt engage, from then on I cant make it work unless I knock the gas tank underneath.

I'm on a budget and I plan to fix it myself I was wondering what opinions the forum members here might have on the problem and if fixing my fuel pump will solve the problem. Or if its something like a relay or a switch or something like that. I have checked the relay and i dont know I didnt notice any problems its just a little black enclosed box, and I checked the fuel disengage switch thats in working order.

Much help is appreciated and when I do take it out I plan on taking detailed pictures and posting a tutorial because I've read so many that rock and I hav'nt found any with pictures that make me feel confident about doing the work myself. But I'm sort of mechanically inclined so I figure its something I can take care of in an afternoon.

 

[techieman33]

have you replaced your fuel filter recently? I would change that first it could be clogged making your pump work for a bit to build up pressure.

 

[Reservetwo38]

No I hav'nt ever checked one of those I'll get on it, thanks techieman33!

 

[Reservetwo38]

Update to "is it my fuel pump?"

Thanks for your reply, I went ahead and replaced the fuel filter and the problem has gone away. Although I've stopped at a couple of red lights and the engine makes a humming sound louder than softer and repeats almost like its working extra hard to keep the car idling. Any thoughts?

 

[rscamaro73]

I'd replace the fuel pump BEFORE you're stranded.

Just make sure the tank is pretty empty before hand

Yeah....I had to toss over 12 gallons of varnished/gummed up fuel from my tank. Glad the filter caught it all. If the tank is nasty, get it professionally cleaned (H.D. truck radiator shop will do this, ran me $70 in Trenton, NJ).

Make sure you have the right tools for getting the fuel line fittings off.

 

[Reservetwo38]

Fuel pumped changed, new idle question?

Thanks Rscamaro73, I did go ahead and replace the fuel pump over the weekend, wow those lines were stuck a few of them took me a good 45 minutes a piece to remove. All in all the job was way more work than I thought it would be, but now it seems to be running without any problems. It idles at 700 rpms and starts up effortlessly, but I wanted to mention and ask: If I let it idle for over a minute or two it seems to idle abnormally, almost like hiccups, is 700 rpms a good idle speed? Its just it builds itself up then lowers and back and forth, its made me nervous so far, but I got the car recently and I dont know what a normal idle sound is... I know lame, this is my third explorer and I'm still learning.

 

[rscamaro73]

Maybe pressure regulator or some trash is in the fuel rail or the injectors need cleaning ??

Did you check your fuel pressure with it running ?

 

[shellbees]

this was helpful. I will try fuel filter and check pressure. thanks