Check Engine Light..Coil Pack...

1994 Ranger 2.3L..Actron Scanner(OBD-I), tells me code 224..primary coils.. Already replaced one that a mechanic told me was bad..no difference. Check Engine light on(173kmiles on truck), Using a Digital meter I cannot get the correct readings from the new one or the old one.. The truck has 8 spark plugs..2 coil packs... Any help on troubleshooting. I will try an analog meter tonight..
thx..