Won't start in wet weather

Please provide information if possible.

1990 B2200 will not run on wet and damp days. Vehicle will start and run for approximately 1 minute then stall and will not start. let it set for a day and it will run like a champ till the next rain day. Vehicle has primary electrical working fine. If I drip gasoline into the fuel injection it will run until the gasoline is burned off. Seems as if the fuel pump stops working. I have replaced the fuel pump and the fuel filters but this does not correct the problom.Vehicle has 81000 origional miles. Any assistance with this issue will be greatly appreciated.

maybe you are getting water in the gas line

Been my experience that ALL wet weather problems are electrical.
I have had bad coils, bad wires, bad solenoids, poor ground wire, and cracked cap cause rain related problems.
Chase your injector wires, fuel pump wires, and fuel cut off solenoid wires.

It seems as if I loose power to the fuel pump when it is not working. Does anyone know where any connections I could possibly check beside the one on top of the pump itself. I don't know the complete Schematic for the pump wiring. Thanks for your responses. I have power at the coil when it acts up, and also at the distibutor. just no power to the fuel pump.

Altho problem is probably electrical,might try one more thing.Put a can of Dri-X or similar fuelsystem cleaner that takes moisture out of ur tank and fuel lines.U maybe getting too much moisture causing fuel pump issues.Also,if ur losing "power" to the pump when engine sits up,mau not be getting enough pressure to supply injectors.Is gas cap seating good and tight?BJ

Truck acted up again today, Used a test light and found that thier is no power to the fuel pump as expected. All fuses were good and with power. Used a jumper wire from the fuse box to the fuel pump and the truck ran like a champ again to get me home. Now what I need to Know is where the power to the fuel pump comes from? Ignition switch? Fuse Box? Coil? fuel relay? And where this item located so I can further my testing? Since this is a wet weather problom it makes troubleshooting tough because you can only work on it when your broke down on the side of the road. No issues when it is Sunny out. Also tried the dry gas but it didn't help at all. Any assistance would be greatly appreciated.Thanks for the help all.:confused:

All electrical wiring for anything in rear of truck exits the cab of the truck in the bottom rear of the cab. U might want to check and see if there is a frayed wire that gets wet and shorts out the fuel pump. BJ