‘86 300E wont start on first cold day.

Today was the first cold day since I bought this car a month ago and this morning it wont start. It went down to the mid 20’s while previously it has started fine in the upper 40’s. I have noticed two symptoms previously, first, it would have a high idle for 20 to 30 minutes after starting cold(even after the engine was fully warmed up), and second, it would feel sluggish accelerating below 2000 rpm. I have replaced or checked the following: new plugs(Bosch copper), new plug wires, new cap and rotor, checked coil primary and secondary resistance(both in spec), checked for spark from coil wire to a ground(seems fine), checked crank sensor resistance(in spec), checked coolant temp sensor(both terminals at sensor in spec at 6K ohms at 30F), checked 4-pin temp sensor connector at ignition module and found the following: pin 1 to ground 6K ohms, pin 2-3 700 ohms, pin 1-4 infinity, and pin 4 to ground infinity(could this be right?, isn’t pin 4 a ground?) checked OVP relay and fuse(fuse is fine and relay is dated 1997), engine cranks at normal speed. Pulled the plugs and they were wet with gas from all the cranking so I know its getting fuel. Leaning towards ignition problem since using starting fluid has no significant effect when cranking. Could the coil be bad even if the resistance is in spec and produces sparks? Could the ignition module be bad even if the coil makes sparks and is there a way to test it? Any other temperature related sensor to check? It should get back to the 50’s this weekend so I’ll wait until then to start it. Any suggestions?