This has happened to me twice now in the last week. I have an 81 with the 350. The car starts up fine at home, then i go and drive it for about 15 minutes or so, then when i go to start it again after it sits for the first time was like 15 minutes and the second was like 90 minutes, it wont start. it seems to turn over fine but wont fire. it smells like gas so im guessin its flooded. after letting it sit for a little bit it would start up. what really causes this to happen? thanks

 

you need to check your timing it should be at 8 degrees on the timing mark.

 

Check to see where your choke is set both with a cold engine, and after your 15 minute wait. Could be that the choke is closing back down too fast, or closing off too much for a warm engine. If your choke butterfly is closed fully after the 15 minute interval, back it off to open it more. Your choke could also be wound a little too tight and not even opening completely in the first place. And with a warm engine, you hardly need any choke at all.