The next time it doesn't start try to determine if the fuel pump is running at all. Look at the fuseblock at fuse #7. Is there any sign of heat damage? Check the inertia switch. Is it on the Lambda counter and does it have a splotch of white paint? I see you are in Nanuet, NY. I am about 15 minutes from you in NJ. There are several Delorean owners nearby. One is in Pearl River on Town Line Road under RT 303. One is in Nanuet. Another is in Congers. We had 2 for the parade in Tappan last year. The local club is the DMA.
David Teitelbaum