My guess is: Each tank has an electric pump, so there is 2 pumps....and the mechanical lift pump on the side of the motor makes 3 pumps?
found this:
92 F-150 4.9L Inline Six fuel pump not activating, and not getting Spark.
I've tracked the problem down with the help of several guys from this page, so Thank You! I've got the Fuel Pump working by hot wiring it, so I know it works. But I tried starting it, and now I'm not getting spark. Several guys said the EEC, but I'm trying to test what I can to narrow down the problem. Several websites and the Haynes manual said EEC relay which tells the fuel pump to engage when the key turns over. The EEC Relay is shown to be a brown wire harness on the driver side fender, but when I looked at it, it's got a cap on it that doesn't look like it has any connections to it. I've also been told the Ignition Control Module, which looks as if it could be the problem because a lot of moisture has gotten to the area on the driver side fender. I'm basically asking how to start the truck, but have so many side questions, like which part could it be, and which part deals with both the fuel pump and getting spark. Both could be bad I'm sure, but I want to work 1 problem at a time. I'm getting fuel now because u Hotwired the pump, but one of these things getting fixed would eliminate the Hotwire and I could just hook it back up properly, but then again, I don't know if I'd get spark. Can anyone offer advice? I'd really appreciate it!
and...
It should be a usual black square relay in the power distribution box. Try swapping in the one from air conditioning.
If another relay is also getting hot, I would think it's been rewired with too much power going through.
A lot of them are set up to have 12 volts for the 2 second prime then 6.5 volts for constant run. I just remember reading that somewhere, but you could see how it might overheat a relay.
You can also turn the power distribution box over and remove the bottom to see if there are any wiring problems underneath there.
That's assuming your truck has a power distribution box - beside the air cleaner box ?
http://www.alldatadiy.com/about_alldata/index.html
https://www.f150forum.com/f93/fuel-p...ne-6-a-195897/
or from Ford directly
https://www.f150forum.com/f12/figure...m-ford-359732/
how to:
https://www.f150forum.com/f12/figure...m-ford-359732/