Fuel pump primes intermittently.

[choctawcwp1]

94 explorer 4x4 fuel pump primes sometimes. once it starts it has never stalled, so I was wondering if it is something other than the fuel pump.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 91-94 section. The pump is supposed to prime when you turn the key. The pump runs continuously when the engine is running.

 

[MrShorty]

When my '92 did something similar, I was eventually able to track it down to a loose connection in the fuel pump circuit between the fuse and the relay. Being intermittent, it will likely be difficult to track down, but I'd check the rest of the circuit before replacing the pump (the pump is arguable the hardest and most expensive part to change in this case).

 

[TedJ]

I had this problem (on my Explorer and a Chevy Corsica) and it was the fuel pump relay. The contacts start to get funky and they only work sometimes. On the Explorer I had no drivability symptoms, but I happened to get a KOEO code for fuel pump voltage when troubleshooting something else. It turned out that maybe once every 10 times the key was cycled it didn't work.

If you pull out the relay (if its an OEM ford one) and look at the bottom where the pins come out, it should be fairly white. If it has a lot of discoloration and has turned brown that is another sign that the relay is not doing so well.

I doubt it is the pump, especially if it works fine when it is running.

Make sure you get a decent relay, they are standard automotive relays but the cheap junk ones from the chain parts stores are not the best.

When I replaced the fuel pump relay on my truck, I replaced the EEC one as well. I figure they have as much usage on both of them, and if they fail you are going to be on the side of the road. (plus the base on both of them was very dark and discolored) I tossed the old EEC one in the glovebox as a spare...

 

[choctawcwp1]

FUEL PUMP PRIMES INTERMITTENTLY
IT'S FIXED!!!
after changing the fuel pump relay & checking wiring, fuses, & all related items, I found & fixed the problem!!!
It was the battery! It would only hold a charge for a couple of days, so I took it out & found it had bulges on the side. So I took it to auto zone & had it tested. It was bad.
I installed the new battery & have not had a problem since!
Thanks

 

[BrooklynBay]

Thanks for the update! Did you fix this now or within the last two years?

 

[choctawcwp1]

fuel pump primes intermittently

I installed the new battery one month ago!
It primes & starts every time!

 

[rodb]

My fuel pump whines all the time when running, is that normal ?

 

[choctawcwp1]

fuel pump whines

Yes, on some vehicles they do whine a little.
I would change the fuel filter & see if that solves it.
If the filter is clogged it will make the fuel pump work harder, trying to gas thru a clogged filter.