2002 pontiac aztek: drive it for a while, stop and shut down. Won't re-start, will crank. Wait 1/2 hour it will then re-start. Problem is intermittant and seems to be heat dependent. Have already replaced the ICM, and Temp Sensor. Brought to a dealer, no error codes. Now thinking it might be fuel pump. Any suggestions?

What's missing ? Spark or fuel pressure ? Do you know how to test for these ? Video's on youtube show how to diagnose a crank no start .

If your saying the starter motor won't crank, then check the starter motor motor wiring circuits. Make sure battery has a full charge and battery connections all good. If it cranks good but won't start, have a helper crank it while you check for spark at the spark plugs, where applicable. Also, check for proper fuel pressure and fuel injector pulse.

Have you scanned the computer for fault codes?

It could be the ignition module in the distributor or the pick up coil mounted under the distributor on the shaft. could also be the coil you may need a mechanic

you have a wiring problem. maybe in the conbination switch or in the fuse box area.

I had the same problem . on my 2002 silverado it turned to be the fuel pump failed because the fuel filter was clogged. I did the work myself could saved myself 219.00 and labor if I replaced a 7.00 $ Filter .

possibly faulty crank angle sensor.

Check voltage to the battery, and starter. you should have around 12.3. From there start checking the fuses under the hood of your vehicle there are 3 ignition fuses and a crank relay make sure that they are working completely

check to see that the cables and nut are clean at the little power post under the hood, it sounds like you have a bad connection somewhere , if you continue driving does the problem resolve ? get your charging system checked - most shops check it for free at least around here

the radiator cooling fan is not working