Engine problems

Next time it refuses to start don't wait for it to make up its mind-do below immediately to determine if its fuel or spark problem

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, cap and rotor, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing

As far as the no crank issue, I'd check the starter circuit. Check available voltage at the starter, key in the crank position. Make sure tranny is in neutral and a functional e-brake is set.

With no start, extended crank, Have a helper crank it while you visually check for spark at the plugs. If you have spark everywhere, use a gage and check fuel pressure. Any applicable mil codes?

The wiring diagram is for the starter circuit, w/o antitheft.