Two days ago:
Engine turned over normal speed then almost slowed to a stop before starting. Then ran rough for about 1/2 mile. Drove fine for rest of commute to work and back home (9 miles) no problem.

Yesterday:
Car did not start in the morning. Turned over at normal speed. Battery voltage was 12+ . I took starter to parts store and it tested OK. Car started after I put the same starter back on last night. I tested voltage across battery with car running and voltage dropped from over 12(off) to 11(running).I suspect alternator because I replaced battery and cables few months back. All connections are clean and tight.

Today:
Car wouldn't start this morning. Turned over at normal speed. I tried using a battery charger, no help. I tested for spark at the plugs and had no spark. I started troubleshooting the Volvo/Chrysler ignition per Bentley Service Manual.
1.Visual inspection- passed
2.Vacuum line to ignition control unit(ICU)- passed (per visual inspection)
3.Power and ground to ICU- passed
4.power to coil- passed
5.coil resistance- slightly high (book calls out 1.1-1.3 ohms found 1.6)
6.ICU switching function- with ignition on, jump terminals C and B on hall sender connector- This did not produce spark at spark plug. I have tested this in the past and was able to produce spark so I don't think I screwed up the test. I am confused about how this works though. I thought the rotor had to be pointing to the correct plug terminal for that plug to fire. This test did not require aligning rotor.
7.Power to Hall sender- passed
At this point the manual says if there are no wiring faults and coil is working the ICU is bad.
Two hours later car starts fine. I drive toward parts store for free diagnostic test and car dies a mile from home. I carry alternator to parts store and it tests OK.
I'm sure the car will start just fine in the morning after I pay to have it towed home. I am not sure what to try next. Replacing the ICU seems fairly drastic at this point, but would be thrilled to pay the $$$ if it is the problem.