Ford Repair: Ford Plugs will not fire, coil pack, ford ranger

Question
Ford Ranger 1994,  2.3lt engine 4cyl.  I have replaced the plugs, coils and plug wires and the first and forth plug still will not fire on the left side of the engine. This engine has 8 spark plugs total.

Answer
Charles,

I would check the primary wiring to the coil pack for a signal from the ignition module. It is also possible that the ignition module itself is bad. The only way to know for sure is to use a oscilloscope and view the signal into the ignition module and then out to the coil pack.  Since most people do not have a scope I would find a good mechanic who does.