You need to fine out if you are loosing spark or fuel. So next time it keels over jump out and lay a wire on your valve cover have a friend turn it over if you see spark you got spark. If not I would look into thing like the igniter or the coil.

When it dyes is your fuel pump priming? Are your injectors clicking? Put a screw driver on the injector and the other end on your ear (not the sharp end).

Any codes?

Vtech?