Why won't 85 190e start when cold with out using starting fluid?

The 1985 Mercedes-Benz 190E may not start in cold conditions without starting fluid due to several potential issues. Common reasons include a weak battery that struggles to provide sufficient power in low temperatures, fuel system problems such as clogged fuel filters or failing fuel pumps, or issues with the ignition system like worn spark plugs or a faulty ignition coil. Additionally, if the engine oil is too thick due to cold temperatures, it can hinder engine rotation, making it difficult to start. Regular maintenance and checks can help identify and resolve these issues.