Intermittent Starting

[tayho]

1999 Tahoe

Will turn over with authority. Have fuel at intake. Clock resets to 1:00. Not sure on spark. Couldn't hold a plug and turn the key at the same time. No idiot lights on. Battery voltage good. Once running, alternator putting out normal voltage. Will start one time and not the next. No ryhme or reason. Will there be any codes if the Service Engine light has never come on? Any ideas on what this could be if it is not turning on an idiot light? Has only stalled out once while running. But have driven it again today with no problems. In fact, it's idling smoother than it has in a long time. Thanks.