I would look at the EHA current first to verify an active system and second to verify cold start and warm-up enrichment. See my article in the DIY section "evaluating engine controls". If there is no current suspect the OVP relay.
If fuel delivery is alright then I would suspect a secondary ignition problem. Dist cap and rotor or coil.
Bosch Master, ASE Master, L1
33 years MB technician