Starting question
 

I have been having an irritating problem with my '89 300SEL. It takes about 3 to 5 seconds of cranking for the engine to start, cold or warm. When the car sits in the garage over a weekend or longer, it takes less than 1 second of cranking for the engine to start. The strange thing is when the car sits in the garage overnight, it still takes from 3 to 5 seconds for it to start. What could be the likely reason for this? TIA.