01 cummins cranks but even with starting fluid won't fire up what could it be

What is your question?

it acts like its not making any compression. even if my injection pump was bad because it's happened before. if you take some 2cyl mixed gas and spray it in the intake. it will fire up. mine doesnt even try. i drove to town. went in and got something to eat. came out and it hasnt tried to start since. the code it throws is no help. everyone says the code is related to the lift pump but in my opinion it acts like the valves are open when they should be closed building compression