i have a 1993 f150 xl. my rear pump works but the sending unit dont not. my front tank pump does not work but the sending unit does. cound the enercia swith cause just one pump to not work?

 

In each tank there is a low pressure pump that feeds your high pressure pump on the frame rail. Each low pressure pump needs to working in order to feed the Hi pressure one.

 

Not on a 1993. Starting in 1990 they just put a high pressure pump in each tank and eliminated the frame rail pump.

 

My fault! I did'nt know they changed that setup. I appreciate your update.
I've been dealing with my old 1988 4x4. i just went through all that pump business only to find out I have no impulse at my injectors. I'm curious to know if this means I have to replace my whole computer in this truck or is it just to much of a hassle. It's just way to much truck to just scrap out. It does'nt even have 100k on it yet.

 

I assume you have checked to see that you are getting spark through the spark plug wires, or gave it a shot of starting fluid to confirm that you have ignition? If the ignition module on the side of the distributor goes bad you will have no ignition, also the injectors won't pulse.

 

Yes, I had it running once by pouring a little fuel into the breather ports. It ran good until the fuel ran out. My helper told me I had real hot spark that day. It sounds like I'll have to replace the computer. I don't have a clue as to how much that can cost these days.