'74 2.0 Won't start (or even crank) when hot Options

[Lavanaut]

First off, I just bought this ride after wanting one for as long as I can remember. This is my first post on this board, and I almost wish I never found it because now I can't get seem to get any work done. Ah well...on to the problem...I'm going to go with the long version, because in my experience more info is better than less with these types of things.

Bought the car from a guy in SoCal. When I got there he started it up just fine. We took it out and drove it, it started just fine. He handed over the keys, I started it right up. I drove it about 10 miles, stopped for lunch, came out and it started up fine. Drove it another 50 miles, stopped for gas, started fine. Drove another 150 miles, stopped, and it started right up. Then I drove it about 250 miles and pulled over to put the top on. Got back in and...wouldn't start. Didn't crank, nothing. All lights came on, headlights worked, but wouldn't start (no clicking either...nothing).

I roll-started it, drove until I couldn't see straight (this was a 900 mile journey to get the car back to Oregon). When I stopped for the night, a quick test showed that it wouldn't start. Came out the next morning, same deal, no luck. Roll-started again and drove the rest of the way home.

Few days later I took it in to my local Porsche dealership. They called me and said that after a couple of hours, they tracked the problem down to "a powered relay that shouldn't have been there". They pulled it out and the car fired right up. Sweet, right? Right...for a couple of weeks. I then took it on a 3 hour road trip, and while it was fine on the way down, on the way back I stopped for gas and got the same old thing ~ wouldn't start, wouldn't crank, nothing. I managed to get it home and let it sit overnight. This time, the next morning, it started! I've driven it around town (read, "short distances") and haven't had any problem at all...it fires right up on the first try. That's where things stand now. Thoughts, anyone?

Oh, by the way, I'm not a "car guy". I've never worked on cars beyond very basic stuff, so please keep this in mind if you would if/when you reply. Me=Noob. Many thanks in advance, I'm psyched to have found such an awesome resource for what I can already tell is going to become an obsession. ;)

Lava