Hard To Start When Warm

1997 Tahoe, 5.7L, 120,000 miles. When engine is warms and sits for 15 minutes or more, it becomes hard to start. The engine cranks, but won't catch on the first try. Sometimes if you crank a second time too fast it will backfire. Starts right up when the engine is cold.

Replaced fuel filter, spark plugs and plug wires. Battery seems ok.

Any ideas if there is a sensor that might be faulty, but not kicking off the Check Engine light? Any other ideas?

Thanks - Steve

Fuel Pressure Regulator. Do a search to see how common it is.

Bad news is that it is under the top half of the intake manifold.

//2000CAYukon