1987 1.8 cabby auto cuts out

Hello well my cabby is playing up essential it will cut out....................... can turn engine over but no ignition by default i gave the coil a smack tried the igntion and it fired back up......... i drove home and it cut out 5 or so times each time i tried to start up and it wouldnt not until i tapped the coil.... and each time it would start up again???????/........................ Now im assuming the coil is to blame so have ordered a new one does anyone else have any ideas why this is happenong i have checked all wire etc for lose connection all are fine and it has a good earth??????? all ideas and help greatfully received........ :dontknow: