Working on a 1991 F150 5.0L, Sometimes the you can hear the electric fuel pump(s) come on sometimes they don't. Are there two fuel pumps in a dual tank truck and if so do they share a common fuel pump relay? It seems to be a random electrical issue. Cold or Hot-problem is still occurring. johnnyrocker

Did anyone check the fuel pump relay?

https://www.google.com/search?q=1991+Chrysler+Lebaron+Fuel+pump+relay

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The pump can be running but not pumping any fuel.
When it stops running you will need to figure out if you are loosing spark to the plugs or fuel to the injectors.

This issue can be different things. This can be an electrical problem, Fuel pump may not be getting electricity continuously, Fuel filter may be clogged, or Fuel Pump is defective.

I would suspect the fuel pump is the problem, it may be sticking at times and this causes a no start. The pump is located inside the fuel tank and it is electric.

It needs to be replaced. It is getting stuck.

Had a problem like this before and it was the computer..But you could faintly smell something like burnt wires..The computer should be down by the kick panel on the driverside..See if you smell anything on that side

when it don't start check to see if the car has spark. Also listen to see if you can hear the fuel pump in the gas tank working. Fuel pump should make a buzzing noise when you first turn the key on for a few seconds. If the car has spark but you can't hear the fuel pump the pump is probably your problem. If you can hear the pump and have no spark I would check the crank sensor. If you cant hear the fuel pump be sure to check the fuel pump relay under the hood in the fuse box before changing the fuel pump. Good luck

Best suggestion would be to put a fuel pressure gauge on and and see what the fuel pressure reads when cycling the key off and on pressure should be 37 to 43 any less then this suspect the fuel pump or an electrical connection to pump. When it acts up and you can not hear the pump running try tapping on the fuel tank.If vehicle starts after that suspect the fuel pump.

sometimes their is a cover/flap under the carpet in the boot/trunk to allow access to the pump/wiring without having to take the tank down.hope yours has one....just a thought,if you hold a screwdiver to your ear and touch the tank with the other end,then someone just turns key to the on position you can hear the pump working.

your truck is a 4.9L, make sure you have power to the front tank fuel pump. is the power to the pump is ok and you can hear the pump run for a second or two when you key the vehicle on... replace the fuel tank selector valve