my cosworth has this starting problem all of a sudden!
last monday to thursday car wouldn't spark, checked everything, couldn't find a problem

i kept cranking her over then it just started to spark, put plugs in and she fired up, its running A1 when it does start

now just sometimes it needs to be cranking over for a good while before she fires up, other time look at the key and shes away!

i replaced phase sensor, crank sensor, distrib cap and rotor arm

still the same

any ideas anyone?