having trouble starting. This is my first (not last) mercedes. Its an 84 300SD. Hot or cold does not seem to matter. When you've waited for the glow plug light to disengage and try to start it either will or won't. Some times it starts right up others you can wait up to ten minutes. The battery appears to be fully charged. I can hear the starter gear engage. I'm leaning towards the ignition. I don't know if this is a common or easily fixed situation? The car has 267,000 miles shes just getting broke in:). I appreciate anyones suggestions. thanks benzbear68