[batkoach]

you could also have a concern with the fuel pump relay intermittently not working . thy turning the key on first and listen for the pump to run before cranking . it sould run for 3 seconds then stop if comnputer does not see a crank signal. if no pump running and long crank time then starts the pump may be coming on after the oil pressure uint see pressure which will connect the fuel pump circuit on most cars and truck gm makes . this may explain the long crank time. how ever i do not have my schematic in front of me to be sure on your truck. check your fuel pump wiring schematic to be sure. i beleive once the computer sees pressure from the oil sender it turns off the relay.