94 ranger 2.3 running on number 2 and 3

front coil packs has no fire at all and back is firing on left side only have changed coils no help tried computer no help installed new ignition module and now it will not fire at all also it would run ok when cold and then start missing like you flipped a switch and sometimes will start out missing what could be my problem and is there any special tricks when installing a new ignition module thanks