1985 ford f150 starting problems

I have a 1985 ford f150 that starts fine when I first get in it but the after I get to where I am going I try to start it again when I come back out and it won't start. After I wait 15-30 minutes then it will start again. Any ideas?

What engine do you have? Does it turn over when it won't start? Is it fuel injected, or does it have a carb?

351

I have a 351 with a carb and yes it turns over for the first few tries and then you can hear that it starts to drain the battery.

It sounds kinda like vapor lock. You might do a search, to see what to do about it, if it is vapor lock. I have never encountered it. Check to see if you have spark when it won't start also.