I had been driving around and went home for 20-30 mins, and as I went to leave again the car would turn over but die immediately. The engine was still warm at this time.

I let 2-3 hours pass now and the car is starting up no problem.
2000 accord v6 ex
Thoughts?

 

It's a 2000 V6 is my thought.

 

ignition coil? Gets hot, dosent work. Cools down, the it works.

?????

 

Oh shoot, forgot to include it.
Yes the 2000 V6 EX.

 

Sounds about right, could you go into further detail on the ignition coil.

 

It's called hot soak aka vapor lock aka winter/ethanol-fuel-gremlin aka no-fuel-return-line problem. I'm fixing mine this weekend (attempting to) by swapping fuel rails + fuel lines from a 2000 Odyssey to include the fuel return. Either that or I'm spilling gasoline everywhere and torching the car.

 

I see, hot soak. I looked it up. Are there other solutions besides swapping parts?

 

The next time it doesn't start you need to immediately check for spark by using a spark tester. If you do have spark, then check that you have fuel going to the fuel rail but pulling the fuel rail bolt after turning the ignition off and seeing if it sprays fuel. Make sure to use a rag to catch it as you undo the bolt. Just be safe.

The problem with intermittent problems is you need to test fast before the problem fixes itself before you get to find the problem. You more or less have three culprits that come to mind...the main relay...the ignition control module...the ignition switch.

 

sounds like main relay to me

 

The car has 197k miles on it, but its been maintained decently. I've owned the car for about a month now, I've been using 89 octane gas. Would using 87 possibly help this problem?

 

Changing fuel grade will do diddly. Octane rating is only for anti knock, if your car runs fine on 87 there is no need to use 89 or 91. There is no difference in power output.

Follow what Holmes mentioned above, check for spark, check for fuel. If you have both the engine should try to fire or at least sputter.

Are you sure the engine is trying to start, or merely the starter is just spinning the engine? If that is the case listen for the fuel pump priming when you turn the ignition to II(ON). You should also hear a slight click sound from the main relay. If the main relay is failing it is common for it to fail in the manner you described, when cold car is fine > drive around > turn off > come back a few moments later> no start. Easiest way to test this is the above mentioned tip from Holmes. Crack open fuel test port, turn ignition to ON and see if fuel gushes out of fuel test port.

If the fuel flows then the main relay is most likely fine.

Check for Spark, if you have strong blueish/white spark while cranking then the coil and ignition system is functioning.

Determine the above basics first and come back with more info.

Also has the car been worked on recently? Or any changes to the car done? Look at any recent work, if applicable.