colin:

I think you misunderstood my reference; there are three terminals on the ignition coil, not three coils. The two small terminals are in the primary circuit, the larger central terminal is the secondary (high voltage) connection.

Ferdman is quite likely correct about the EZL (aka ICU [ignition control unit]). Before exchanging the EZL, perform this test: unplug the coaxial lead that comes from the flywheel pickup, and check that there is continuity of that circuit by placing one probe of your meter on the central pin of the coax cable, and the other probe on the ring. You should see a resistance of approx. 700-1200 ohms. If the resistance is either zero or infinity, you may have found the problem.

Borderline impossible to find a known good one for this engine. Already called MB and they are no longer available, and if they were it would be $2600.

We have found a place that rebuilds them though should this be the problem.

I did test this and did get between 700 and 1200 ohms.