i'd guess the accel parts... check the resistance in the wires... should be around 2k per foot.... if they all check within those lines... then check the coil, should have relatively low resistance on the primary circuit, and very high resistance in the secondary.... primary circuit is the power side to the points side... secondary is power side to dist. cap side... remember if the spark looks weak outside of the cylinder... then inside it probably isn't sparking at all