Just read the other post in different thread where you said you installed a new OVP.
As the problem is ignition related, I presume you have new plugs and leads? Or at least, they were done quite recently. They would make more sense to change than the coil, IMHO, and even when looking good can need replacement.
Otherwise, your mech may beckon. Shouldn't be a problem for him, the engines are quite simple, and nothing unusual about them for a knowledgeable mech.
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black