I had something similar happen with my GP; the first time it acted up at a car show, but it started up on the third try. The second time was months later in my garage at home, but this time the gremlin stayed long enough for me to troubleshoot.
The culprit turned out to be a faulty fuel pump relay. The relay would click and the pump would prime with the key on, but then it would crank and not start, because there was no fuel pressure at the rail. Swapped it for the spare I kept in the glove box, and it fired right up.