You could remove the spark plug wire from from distibutor cap lead comes from the coil and set it about 1/2inch from a grounding point, like a bolt on the shock tower. unplug the gren and violet signal wireplug if your using it , then ground and unground the white signal wire coming out of the MSD unit. Every time you unground the white wire you should see a spark jump from the coil wire lead. If you don't see a spark, double check and MAKE SURE you have a good ground at the MSD large Black wire. I think the instructions are at page 10. I just went through this procedure last week , so it's still fresh in my mind. See if that helps.