4 cylinder mustang help needed

[DaddyBuiltRacing]

Brother in law has a 91 4 cylinder mustang. He bought it with the car having a miss, so he did the regular tune up i.e plugs/wires. That helped some but miss was still there, so he replaced the coils hoping that would solve the rest of the miss. Its still there, the tach doesnt work either. The passenger side coil doesn't spark now, coil has been replaced yet again thinking maybe he got a blem from autozone, same result after changing. Someone told him that there is a part that controls the coils kind of like a resistor box, does anyone know the name of this part or have a picture of it?

[Buckeye1647545503]

Step 1 don't but parts from auto zone

Step 2 check for power etc at coil

Step 3 it most likely need a module

[DaddyBuiltRacing]

He figured it out so you can lock this