[jdl]

There might be an issue with your ignition switch? You need to do some testing, when it refuses to start. Turn the key on, see if you have any reference voltage at one of the engine sensors. It doesn't matter which one, whatever is easy to get at. Crank sensor--cam sensor---throttle position sensor. Unplug the sensor, turn on the key, check for voltage at one of the terminals. If there is no voltage, check for feed going to the pcm. My info showed two feeds, one is fuse B 20amp--in the power distribution center under the hood, hot all the time. The other is fuse cavity 12 10amp in the fuse box, goes hot when you turn the key on. You have to do the testing, when it refuses to start, you can pull those fuses, use a testlite to see if one of the terminals for each fuse is hot. One fuse is hot all the time, the other goes hot when you turn the on.