Autosport Labs

I have had a megajolt installed for quite some time now but have noticed a small problem. I have a 16v vw engine with weber 45 carbs and use a colourtune to adjust the carbs. This is similar to a spark plug but with a window, so you install this inplace of the spark plug and fit the ht lead to the end. However in the 16v head the plugs are located down in the head so the connection the colortune runs into the head. When i run the engine with this connected, there is no problem with cilinders 1 & 4, but when connected to 2 & 3 the lead arcs to the head constantly.

My question is , is it possible that the voltage to plugs 1 & 4 is too low not resulting in arcing, or is the voltage to 2 & 3 too high resulting in arcing.
I have measured the primary and secondary resistance of the coil and all is within range. Is it possible the output to the coils stages is different?

There may well be a difference between the 1/4 coil and the 2/3 coil. After all, everything has manufacturing tolerances

The actual coil voltage rises until the spark gap path arcs over. So the coil itself doesn't really determine it. A wider plug gap, or a fouled gap could do it. My guess is, the insulation on some of the wires is better than others. Bruce Roe