Fuel pump problem.......HELP

[carrerajason]

I have a 1988 Bronco 2. I dont run it very much at all. The original low fuel pump finally went out. 250000 miles So, i zoom to My local O' riellys and bought a pump...by precision...$95. Put it in and it probably worked for 3 weeks......only drove the truck maybe 300 miles. Maybe started it 10 times and drove. Then boom....no worky.... So here what i did.....

a. Take pump out...hook up direct to battery....no worky
b. Take test light out to back of truck..hook up into truck wires to pump ...turn on key....and get the 2 sec light on...so got power there
c. So, my conclusion...faulty pump....just get a new one...under warranty...right?

Now im on my 4th pump. I have replaced it now 4 times. Same thing. Runs great for a while ...then one day ....its out. Now i have a couple questions.......

1. Anyone else use a precision pump? iS IT A POS

2. I turn the key on and can hear the pump for 2 sec. When the truck starts....is the pump supposed to stay on? Mine does when it works....i havent heard that it comes off and on due to pressure anywhere on net....

2. I test the wiring with a light thingy....it gets power...never lost power. Could it be some kind of surge?...its not hardwired (yet) so it has a fuse in the line

3 . Has anyone hardwired one in to just stay on? Its a recovery system..so does it matter if the pump stays on?

4. OR....has anyone put like a external one on...i have heard of a MR gasket 42s.

I hope some one can figure this out. I mean...really 4 pumps all go bad in maybe 15 cranks of engine? A guy at orielly told me that the pump works off the TPS and is supposed to come off and on depending how much load is on the engine. But the same guy had told me that the pump grounded to the tank. ( dont understand how it does that through the o ring). Also ive been told it was the new type on gas.......but i havent seen anyone else replacing fuel pumps one a month in a truck that sits 3 weeks out the month?

On the positive note....i can now drop the tank and instal new pump and reinstall tank in 15 min,.............And yes i realize there is 2 #2s...im just to lazy to change the numberes

 

[The Fonz]

When I turn the key you can hear the pump whine for 2 seconds then nothing.
Might be a stupid question but did you replace your fuel filter too?

 

[carrerajason]

Its clear ...i can blow threw it. I know the pump is suppossed to come on for 2 sec and shut off....but when the treucks actually starts and runs....the the pump come back on. I hear its a safety issue that it shuts off. It is supposed to "pressure" up the sytem...then shut off...so it doesnt keep dumping fuel if truck doesnt start. But i think when the truck is running...the pump come on and stays on....well...mine does when it works

 

[RonD]

Yes, the pump comes on to prime the system for 1 to 2 seconds when key is first turned to on, that is normal.
The ECM(computer) does this, then it uses RPM and TPS to determine how often to turn on the pump once engine is started.

The ECM does not power the fuel pump directly, the ECM turns on the Fuel Pump Relay, usually located in or below the engine compartment Fuse/power panel.
It is in a green connector.
This relay can fail, either it sticks closed so pump is always on when key is on, or it stops closing so no pump power.

The fuel pump power runs from the relay to the inertia switch located inside behind the passenger side kick panel, this switch can go bad as well, cuts power to pump, it has a reset button.
The inertia switch is there in case there is a collision, if there is a sudden stop or roll over the switch cuts power to pump.


Yes cheap after market pumps often fail.