imjrk

Having a fuel issue with an ’85 FI. Replaced both fuel pumps about a year ago, now back to the same issues again. No start, but spraying carb cleaner into TB it starts. Need to again replace the in-tank fuel pump, no fuel being pumped to the filter. I HOPE the inline pump isn’t also toast. Anyone have an idea of why I continue having fuel pump issues? Is there a replacement single fuel pump that will work instead of the two Ford thought was a “better idea” in ’85-86? Thanks

Good old Bill

Sounds like an electrical issue, not a pump issue. The key from off to on is supposed to prime the fuel rail for start ups, after the engine starts then the pump runs all the time. By priming the TB with spray and the engine starts and keeps running tells us the pump is functional. You need to concentrate of the key on priming circuit.

imjrk

Sorry about not being clear enough. When I stop spraying carb cleaner into the TB, the engine stops. No fuel coming out of the disconnected hose at the filter when the switch is turned on. No sound from the fuel pump either. Thanks

klricks

Do you have dual tanks?
I would also suggest to check the electrical items.
-Fuel pump relay
-Tank selector switch on dash if you have duel tanks.
-At the HP pump connections.
-At the tank pump(s) connections

As Bill said the pumps will run for about 3 seconds when the key is turned from off to on. If the engine does not start then pumps go off. There is a way to jumper the relay to force the pumps on for troubleshooting. If not jumped then you will need to have someone switch the key on and off while you test with a volt meter or test light.

imjrk

I hear a "click" from the egine compartment when I turn the key on. I believe it is coming from the drivers side inner fender area. Would that be the relay?

Marvinteck

Yeah that would be the fuel relay. Autozone.com says its Under hood, driver side, mounted on upper firewall.

I ran into a fuel pump problem on my 86. The computer wasnt grounding the fuel pump relay. Check for power and ground at both fuel pumps. If you dont have power there go up to the fuel pump relay to see if its working.

imjrk

Found the "fuel pump" problem, wasn't the fuel pump. Had power into and out of the relay, but not to the pumps. Traced the wire to the pass side of the engine compartment and into the firewall, found a reset switch on the pass. side floorboard in the cab under the dash. Pressed the little white button on the top of the reset, and we had power. Had this truck for almost 20 years and never knew there was a fuel reset switch.

What exactly is the reason for having a reset under the dash in the cab? What trips the reset cutting power to the pumps? The truck was in the shop to have a head gasket replaced, drove it in, when head gasket replaced, no fuel pump power.

Thanks

klricks

That's the inertia switch which should only trip in a collision but can trip during a hard impact of some sort, extreme 4x4ing etc.

imjrk

Just parked in the shop having a head gasket replaced, and I drove it in there. So what tripped it; ??? At least now I know it is there. Does a '99 have something like that? Thanks