No start

Thanks fo responding to my orignal question, I made a mistake when I said cam sensor replaced I ment crank sensor and 4 replacement ignition modules. Several of the garages sasid ignition modules were gone or coils, but when I used them agin they worked, then they stoped working, meaning They agin gave spark then they stoped for awile and 1 day they worked agin meaning nothing wrong with ignition coils or ignition modules so im really confused as to what it could be, several garages could not find any wiring prob, which I suspected, not sure though, any other suggestions would be appreciated