Chevrolet Monte Carlo Forum : “Car won't start after shuting it off, if I let it sit for awhile then it will st...”

It could be a lot of things, hard to say without diagnosis.

who cares...if it starts drive the damm thing...or better yet roll the dice,replace the pcm.....and maybe whatever else comes to your head...hope this helps

It could be the pcm or any of the many on board computers. If a computer is under hood and heats up the resistance in the wire increases and the computer communication will not allow the vehical to start. also check all electrical connections and start the car and give it the good ol wiggle test!

my pontiac bonneville did the same thing, it turned otu to be the crank angle sensor

Absolutely, 100% your car needs head gaskets if the PCM doesn't fix the problem.  Had the exact same problem myself.

bad crank sensor.marty we are here to help out people not to bs them.