Hi, can any one help me, ive recently put an engine in my saphire cosworth, and its only running on 2 cylinders (3+4). Ive checked for a spark on the 2 cylinders not firing, and they have a good spark, the injectors have their 12v feed, and seem to be working. ive gone round and unplugged 1 sensor at a time and they all make a difference to the running of the engine (its makes it cut out). Ive fitted new plugs (genuine ford), replaced the dizzy cap and rotor arm, plug leads are motorsport ones. Can any one make any segestions to what i can check next???

Cheers steve