I have a 2005 Pontiac grand am. I can drive it for 20-30 miles, then shut it off. When I go to start again hours later it won't start. If I let set for a day or two it will start. It isn't getting hot.

Is it getting spark and fuel.

Lol

I don't know what is funny about John's question. Next time it happens, squirt a little starting fluid into the air intake. If it fires, you know that it's getting spark and you have a fuel problem. If it doesn't fire, you have a ingition problem. --- If I had to guess at a probible cause, I would check out/replace the coil(s). They sometimes fail when heated up.

The part I find funny is that I said after a day or two it will start. Which means there is fire and fuel.

The part that I don't find funny is there are 4 things required for an engine to run. One and two are air and fuel in a correct mixture. Three is compression of those two and four is ignition. Sinse air is in abundance and compression doesn't magically disappear then reappear the only two that can possibly be going away is whatever controls the spark or fuel. Obviously you know what you're talking about so I guess my help isn't required.

Alright again.....my car was running. I drove it for 20-30 miles. I shut it off.( mind u this is a repetitive problem, so the situation I'm explaining has happened a few times the same way) when I go to restart it turns over but does not start. I wait a day or 2 and it will start and run. So...it is getting fuel. It has spark, but u r correct that something controlling the 2 is messed up. That's not what u asked in the beginning. Hence my amusement. I just wanna fix the piece of crap for my daughter. I've taken to mechanic and they can't find problem.

That's because you can't diagnose a problem that isn't there. Diagnostic tests can only be done if the vehicle is having issues while diagnosing. Next time the car does this you need to crank the engine over to see if its getting fuel and spark...... I have only seen symptoms similar to this once before, about 3 years ago. It also had a hand full of other things that didn't work only when it wouldn't start. Lady had it towed to three other mechanics and it would eventually start for them so they didn't figure it out. It was on an early 2000s Buick. After chasing the issue I ended up testing the voltage at a few sensors that should have had a 5V reference and it was only 3V. So i tested the ecm input voltagr which should have been 12V and it was around 3V. So I started testing the voltage at the other fuses belonging to the items that didn't work and it was the same thing. It ended up being a bad ignition switch.

When I asked was it getting fuel and spark I figured it was obvious I was talking about when it wasn't working.