Burks

I know my way around vehicles a fair bit but I'm completely clueless on trucks. I'm getting my parents 93 F-150 as long as we can get it running again. It has sat for roughly a year because the power steering lines were blown (anyone know what a complete new set costs?).

Go to start it the other day, won't start. New battery and terminals, the truck turns over but that's it.

So we sprayed some starter fluid in the intake and it'll run until you stop spraying. Guessing fuel issue at this point.

Replaced the relay and the tank switch, still nothing. Plug filter? Replaced that as well.

So we're down to what I can only assume is BOTH fuel pumps being dead? When you turn the key to on, but not start the engine, you can hear the relay (I'm assuming here) trip but no whine from the pumps like you'd expect.

Is it possible BOTH pumps are dead just from sitting there for roughly a year? What else could I be looking at before dropping fuel tanks?

aliens8mycow

It's turning over, and will start with fluid in the TB... new filter, new tank switch, new relay... gotta be fuel related?

Is this year old fuel in the tanks?

Might check in the driver's floorboard area - up behind the brake pedal - there is an inertia switch on the firewall - just for grins, see if it is tripped.

Might also check for codes and see what you get:
https://www.f150forum.com/f10/how-retrieve-trouble-codes-obdi-10907/

Let us know if you get any codes and we can translate.

My next step would be to blow out the fuel lines with compressed air - drop the filter, unhook at the fuel pressure regulator (on the fuel rail), and blow it out. Also unhook at tank and blow back to filter connection.

Nitehawkjr

The hoses should run no more than $50 for both. Yeah it’s possible that both pumps are bad. When you turn the key on are both the eec and pump relays pulling in?
I would start by doing a voltage check at the pump relay to see if there’s 12volts there. Then make sure the relay is pulling in to send voltage to the inertia. Then go to the inertia to see if you have voltage or if it’s tripped. I believe the inertia switch is behind the kick panel on the passenger side on a 93 it is on my 92.After there it goes to the selector then on to the pumps
Also you can put a jumper on the test plug under the hood on the driver’s side firewall from the #6 plug to ground that will force the pump relay on to check for voltage. That way you can go straight to the pumps to check for voltage or do the checks above.

Here is a picture that ymeski56 posted the other day of the plug

1987 F-150 XLT 4x4

Before replacing either fuel pump; I would try this,
put 5 gallons of fresh gas in one of the fuel tanks,
have a new can of Starting Fluid ready, have someone start the engine spinning,
spray starting fluid lightly into throttle air inlet, keep it running with the fluid until the fuel pump gets primed and the engine runs on it's own, this may take 20 to 30 seconds of spraying fluid to get it primed.

The fuel pumps did not just go bad from sitting for a year!
That would be rare.

The gasoline is STALE though!

The Power Steering Hoses are not that expensive,
one is a High Pressure Hose with clamped-on fittings and
the Suction Hose is a open-end rubber hose cut from a spool.


Let us know.

Nitehawkjr

If it was my truck I would see why the pumps were not coming on when you turn on the key as I can't see how they can prime if they are not coming on?. As you asked if it was possible for both pumps to be bad though highly unlikely they could be. But more likely you have an electrical problem.
On my 92 when I bought it the PO told me that the front tank didn't work but the back did so I put 5 gallons of fresh gas in the back tank found out that neither pumps were coming on. It had an electrical issue but also had two bad pumps, so I replaced the front tank and pump now I have a bad pump with 5 gallons of gas in the tank.