You can go under the hood and find wire #55, I think, it is the one that feeds power to the heater pump, and the spark coil. hook a temporary wire to the 24V of the battery. Use this to energize for the tests. The easiest thing to do is disconnect the power plug from the pump, unscrew the wire from the spark plug, and hold the high voltage wire 1/4 inch from the grounded metal like the air cleaner, and energize. You should get a continuous fat hot spark. If this works the coil is OK. Be careful it is alot hotter than a car ignition coil and can give a very nasty shock. If you have that, then unscrew the spark plug from the turbo snout and re-connect the HV wire to it, lay it on the air cleaner or wherever so the outside of the plug is grounded. emergize and you should get a hot spark on the plug. If this works the spark plug is OK. disconnect the power plug from the spark coil. connect the power plug to the pump. disconnect the fuel line from the turbo snout. energize the pump. fuel should squirt out. if so, the pump is at least working, if not good. The only thing left is the spray nozzle. remove it and check that it sprays fuel. If all of this works, I can't tell you what to do, need someone who knows more about it.
as far as my plug, mine is shorted. I ordered two from TNJ murray last week. He says he has good pull outs.