Reminds me of the Pinto I had when I was young and poor but on my own. It would run great until it warmed up then if you turned it off, you could not get it started again until it was cold. I put up with it for months while I worked on it nights and weekends trying to track down the problem myself or through local gas station mechanics who were much cheaper than a dealer.
I finally took it to the dealer, willing to pay the big price (so I thought), before I could get back home, the dealer called and found the problem. A cracked plate in the distributor which caused a short when the metal expanded through heat. $75 bucks latter and I was good to go. I was so pissed that I wasted all my time trying to find something I'd have never found with out the dealer. Turns out the dealer knew that that was a common problem for my model year.
I love to fix things myself, but now I'm careful to keep in mind you can't be a specialist in everything....and sometimes you need a specialist...