Crank no start

I checked both wires on each coil connector and they are both getting 13 volts. Is that normal?

I checked positive wire coming from the coil on the plug and it showed 13 volts. I also checked the ground wire on the plug coming from the PCM and it also shows 13 volts. Is that normal? On all coils while the car is running number one two a number four coils are not firing in those cylinders, but when I switch them around they start firing.

The tachometer is working.

Sorry I'm not tech literate when it comes to circuits and stuff like that. But if I have voltage coming to the ground wire on all of the coils from the PCM which is 13 volts what does that mean?

One more thing; if I'm wrong here then how do I check for signal from the PCM? I don't know if it's ohms or voltage or what it is.

Let me see if I'm getting this right. So if there is voltage at the connector to the PCM then the PCM is the issue, correct? Because all of my coils have the same voltage on both wires and still 3 coils are not working.

Okay. One more thing; is there a diagram of the plug I need to look at? Because all my wires are discolored from age.

Sorry, I meant connector at the PCM.

Okay, I'll have somebody look at it for me and explain it to me because I don't know how to read those diagrams. But thank you and I'll let you know what I come up with.

Do I need to unplug the connector to the coil before checking for voltage? I just realized that's where my voltage could come from on the ground wire.

Okay, now I understand how it works. Thank you so much.

I checked all the power wires going to the coils and none of them have a 5 volt reference. What do I do next?