View Full Version : Several Times Coils Damage In 1week

10-13-2003, 02:14 PM
I have a 12A Rotary engine in a 1973 datsun fastback. I installed 2 MSD Blaster II coils. The car ran great in the shop, but by the time I took it to the track it wasn't reaching 10,000 to 11,000 rpm's like it was. Because it was night time we were able to see that the trailing coil was arching. We went to the track (Wednesday night) for a test run and had no high rpm reves. At this point we noticed that the leading coil was now arching as well. bad night went home. The next day we installed 2 SS blaster coil's, the problem went away. Saturday we went to the track, started the car warmed it up tried to get the rpm's up and again it would not rev up. Opened the hood and found the trailing coil arching again on the bottom opposite of wires. We think that we may have an iginition problem or a bad MSD. By the way we are using 115 NGK plugs for nitrous. What do you think? Help

10-13-2003, 05:51 PM
The reason that the coil will arc at a different location other than to the plug is because there is too much resistance on the secondary side, which consists of plugs, spark plug wires, cap and rotor. The spark is finding the easiest path to ground and that is where it is finding it. I would make sure that the plug gap is not too wide, make sure the plug wires do not have too much resistance and that the engine is well grounded to battery as well to chassis or frame. Make sure that you use a good boot and that the terminal is properly snapping to the terminal in the coil. Once it arcs at the tower then it is recommended to change the boot as well as the coil. Being that the coils are less than 1 year, I would recommend exchanging them through where you purchased from, or send them in to us.