I would also take a hard look at the power and ground circuits. Could be when you put it in gear and the engine shifts when you step on the gas it is pulling a wire in the harness. If it was heat related I would think it would also die if you let it idle. I cant imagine the temperature would change in a 30' drive.
You can locate the harness that has the wires for the crank and cam sensors and try moving it around to see if you can make it die.
When it wont start check for power and ground at the connectors for the sensors.
Not sure if Chevy had the same setup but on the Pontiac's and Buick's there is a ground junction in the drivers side door sil that gets all green. You could get to it by pulling the carpet back. I saw several of these on the Pontiac's and Buick's. The tip off was that usually the power windows or heater or something else didn't work or the windows would be real slow.
It was a connector with a metal blade that connected a bunch of grounds together.
Artificial Intelligence is no match for Natural Stupidity
Last edited by T-bucket23; 07-09-2012 at 06:15 PM.