diagnosis help

[Nathaniel Merrill]

Folks,
 Last three days I've been getting intermittent check engine light - after a few minutes of driving, it will start coming on, then off, then on, then off a while, then on a while...
Gone at restart, repeat.
Today after work, car cranked with no start, repeatedly.  Then last ditch crank before I called the truck, it fired right up - check engine light on.  It was running a little rough at first, then drove home fine.  Shut down resulted in several cranking repeats, then start again.
Thinking crank position sensor?  Not sure the car would run ok if crank position sensor was intermittent though.
Hall sensor?  Car has been a little rough at start up lately, which I think started after new rotor and cap install.  Could have f'd something then.
Off to pull codes now, but any insights to speed my diagnosis helps.
Thanks
Nat