car: 1987 300E

symptoms: car is hard to start in the AM, requiring much cranking for a minimum of 2 times. The first attempt always results in the grumble as the built up fuel is blown off. The second attempt results in sputtering (with gas pedal to the floor) before the idle hits 500rpm and the engine takes off.

parts already replaced:

Fuel Pump Relay
OVP relay
Cap/Rotor
Plugs
EZL ignition unit
Crank Position Sensor

What could be causing this? I should note there is another post on here about a coolant leak (possible head gasket?) that I already posted and plan to address. However, I can't tackle that problem just yet and still require the use of my car to get to and from work. This morning when I attempted to start the car, it would not "catch" and sputtered until the battery wasn't strong enough to get the car going - I'll be jumping it tonight.

Should I address the coil first or is there somewhere else I should start looking for the answer to this problem? Could this be connected to a vacuum leak somewhere in the system?

Thanks for your help,

John

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87 300E
202k on the clock