My truck has stalled a few times because the fuel pump is working when it wants to, also has failed to start due to the same issue. Sometimes you can hear it pressurize sometimes you can't Switched the relay out with the horn relay, horn works with the fuel pump relay. I am thinking about checking the connector to the fuel pump. Currently I am siphoning the gas out to drop the tank. What could cause this? 1992 F-150 with the 18gal center steel tank.

 

As you already stated it, the pigtail connector could be the cause, the pump itself could be also failing. There is also the FPR (Fuel Pressure Regulator), i have heard of it but i'm not even sure all the models/engines (carbed or injected) have it. So there you have 3 possible causes. Add to that a gummed up fuel filter.

 

Fuel filter and pump are new, and the fuel pressure regulator is on the fuel rail.

 

You have already checked what I would have suspected. Don't forget to check the part that the relay plugs into. It could be corroded causing an intermittent problem. I had a somewhat similar experience. My truck had dual tanks so it was easy to just flip the switch and continue.

When I finally got around to it I found that the wiring connection, the actual plug part, had become loose on top of the fuel pump connector. I just cleaned it up and loaded it with dielectric grease and it snapped back on nicley with no further problems.

Does your fuel level indicator work properly when the pump fails? If it also goes out of wack it would indicate a possible loose connection like I had.

 

Haven't really paid attention since I was trying to steer it to the side of the road lol

 

I had an issue like this on the same truck. Since you don't have dual tanks you may not notice one additional connection. Just to the right of the headlight switch and behind the plastic of the dashboard, there is a connector that is usually used if you have dual tanks. When you have dual tanks there will be a switch in the dash just to the right of the headlight switch. If you don't have dual tanks, there is a plastic piece that just connects the wires together behind the plastic.

For me it was those connections that were loose.

 

I actually have the switch because I got a new junkyard piece but its not hooked up to anything. I will have to check it out when I get home

 

no matter if you use a switch or not, the wires must be connected to start the pump. So either connect the wires to the switch properly or just connect the wires without the switch and see how the system performs.

 

does the 92 have a fuel pump relay like the 87-91 trucks have?
they are known to get cheesy connections under the relay and loose power.

 

They do...I have a 92 F150 and had this problem.

 

Like connections under the box? Pulled the tank down, cleaned the connector and whatnot, still intermittent.

 

Brand new relay, fuel pump, filter, power is just intermittent and it sucks.

 

Well, since you already ruled out everything else, you could be looking at a ECM failure. A tranny that's acting up (mostly the E4OD auto) will cause weird effects. My truck was recently showing up a lot of strange behaviours and all was caused by the lack of 2 qts. in the tranny.

 

Try connecting a fuel pressure gauge to the fuel rail, then secure it a bit with twine or tape, so that you are able to drive around with it.(then your truck will look like mine) Next time the truck dies see what the pressure is on the gauge. Just saying, may not be the pump (fuel) after all

 

just for the heck of it, take a close look at your ignition switch.
i have been seeing a lot of bad ignition switches lately. they seperate and loose connection making the vehicle do weird things while driving down the road..