Issues with Fuel
 

I have a 1988 B2600i, 4x4. And Im having issues with the fuel pump. The pump wont come on unless I use a jumper wire and jump it to that yellow wire that is used to prime the engine when depressurize the line. But truck still doesnt want to start it acts like it wants to start but thats it. The fuel rail is getting plenty of fuel and the overflow has plenty of pressure aswell. I know Im getting spark just cant figure out why the truck will fun if I pour gas down the intake manifold and will idle and rev up but then stalls out eventually. For some reason I cant keep it running without stalling the motor. Will see about changing out plugs with new ones. The plugs that are in there are old. New plugs cant hurt it to get better fire. Has anyone had any problems like this with theres?? Any help would be helpful or suggestions. Thanks[:@]