1988 ford l8000 diesel 7.8l injection pump sticking

Hi everyone my dad had a 88 l8000 6 wheel dump the truck was used to tow a 20 ton tag with a john deere 590d 30k excavator it did it for 10 years but the rearend was the weak point it has some rearend lock lugger or somthing not sher well anyway when It poped the 4 th time he had it fixed but then bought a tractor and had hd a pintle mounted to the back back truck is perfect so the l8000 has beeen sitting since 2001 I wanted to get on my own and need a dump so I changed the oil put new fuel tanks on it all fuel filters put new batterys in it primed the fuel system up to the injection pump but thats where im stumped I cant get anything past it to the injectors it runs off either and silicone. Disconected the electric fuel shutoff actuator and felt the arm on the injection pump for the shutoff and it moves but feels loose doesnt feel its doing anything inside a buddy has a identical truck and I disconnected the shuttoff and his feels a slight tension just when its about closed. So my question is what do I do anyone have this problem before ????? Please help

1988 ford l8000 diesel 7.8l injection pump sticking