Bad cylinder

[Mcteem]

I have an 1988 gt AOD that keeps fouling out the#5 spark plugs. Some background the car has a v-1 vortech SC 80mm throttle body, Edelbrock upper and lower intake manifold and 36lbs injectors. Car runs and drives fine but after a few minutes of driving the plug covered in carbon. Is this a dead cylinder issue?

 

[broncojunkie]

Definitely could be ignition or injector. Try pulling the plug and cranking it to see if you're getting a good spark. You can also swap plug and wire (new ones or simply switch from a different cylinder) and see if the problem moves to that cylinder. If nothing changes, then swap that injector with another cylinder and see if your problem moves to that cylinder.