Went to start the m20b25 today, fitted battery turned key, click fron the starter and all dash lights go off. Strange

i turned key back and forward. Nothing at all. did it again and lights came back on, went to start same thing again

3rd time it turned over with plenty of speed but didnt fire deffintly not a flat battery, its fully charged and about 6 month old. 5th time it did the same turned over with plenty of speed but didnt fire.
Then 6th time it turned over and fired straight away
could this be because the ecu hasnt had power for a few weeks ?
obviosly when the car becomes my daily i want it to be reliable
