1988 Chevy Truck electrical computer and / or?

Donated 10 $$ by credit crd. Before entering this page no start condition. Runs on wd 40 or gas placed in tbi momentarily, changed tbi fuel pressure relay and fuel pump. Raised fuel pressure placed nail in return fir resricted orifice, by passed fuel pump. Works no start, injectors will not fire, injectors will dump when grounded. Installed new battery, truck has been laid up 4 years for faulty
fuel pump(changed) with ignition fuel pump will not operate, checked fuses ok, need to check voltage imput at computer? Everything else works on truck.
just a no staqrt condition
opinions and advice req2uested thanks
william stroud