On occasion, my 4.6L powered '99 Crown Vic will refuse to start. The vehicle has approximately 130k miles on it, and this starting problem has been an on and off issue for about the last 40k miles. For example....went to church today, got out and the car wouldn't start. Cranks over just fine, but won't start. I get under the vehicle and can hear the fuel pump run for a few seconds when the key is turned to the on position, and can feel the fuel pump relay under the hood pick up when the key is turned, but the car won't start. If you wait a half hour or so, the car will start. I don't know that the time has anything to do with it, because in the meantime I'm opening/closing the hood, doors, etc., possibly jarring something (faulty contact?). The last time this happened (about 2 weeks ago), I moved the shift lever around as a last ditch effort and the car started. Don't know that this has anything to do with it either, because I was under the understanding that the neutral safety switch on the steering column would not allow the starter to engage if the switch was out of position. The car always turns over without hesitation, just won't start when the problem occurs. As I was saying, it is intermittent........before the 2 incidents in the past 2 weeks, it hasn't acted up for about 14 months. I was thinking maybe bad contacts in the fuel pump relay, but am leaning away from that idea because the car is driven every day and one would think that the contacts, if bad, would exhibit failures more often than they do. Any help/suggestions would be greatly appreciated.
P.S. I have never seen a service light on the dash indicating any kind of faults/errors.