I have a 91 D250, in excellent condition. Drives well, loves weight, but does not love its current fuel pump. I do not want to drop my whole fuel system in order to replace it, that would be a pain in the but. I had a friend tell me that I could hook up an external fuel pump from the fuel line to the engine in the engine compartment. Is this possible? isaac@kainsphotography.com

 

Correct, you have to drop the tank to replace it. That is the best option in my opinion. I've never liked trying to hack in an external pump. Seems kinda risky.

Honestly, dropping the tank is not that hard. I don't know why people always dread doing it [&:] I could make a fortune around here changing fuel pumps...it's really not bad at all. Some people also different route and pull the bed. I've done it both ways, and I'd have to say that dropping the tank is easier and takes less work to accomplish.

There's a write-up here for the procedure: https://dodgeforum.com/m_402587/tm.htm Granted, it's for a 2001, but it's really not that much different than your '91 is.

Does the pump run at all when you turn the key?

 

I dropped the tank on my 86 to replace the rubber lines and it wasn't a pain at all. If the pump is dead and you can't just wait until you're low on fuel though, that can be quite a pain I imagine.

Time for some jugs and a syphon hose.

 

Or if it's not dead, but too weak to run the truck...you can jump the relay and let the pump empty the tank for you.

Usually if you beat on the tank with a rubber mallet, you jolt the pump enough for it run for a while. [8D]