Re: Back Cylinder Not Firing !
I think Hoople was right on, the first thing I would do is unplug the pc and plug the ECM in direct just to see, because pc is a go between, if it still does not fire it rules it out. Another common problem I[ve seen when only one cylinder fires is a break in one of the injector wires close to the plug, you can not see it because the plastic coating is in tack, it's easy to check with a wiggle test, but you said it's electrical so forget that, what trouble codes are present? I would check the trouble codes with the pc unpluged.
Hollow Points - For Those Who Care Enough to Send the Very Best