i swapped out cams, adjusted the valve lash, and set the timing and belt tension. cranked the car up, everything looked good. shut it down & bolted on the timing cover...no start. i could hear that the main pump wasn't running, so i knew it was a spark problem. pulled the hall sensor plug on the distributor (3 wire sensor) jumpered two of the contacts to trigger the spark, saw the spark and the main pump ran briefly. checked for 12vdc on the third contact (nothing...), checked for 5vdc on the middle contact (good). checked the fuses (all good), scratched my head and pulled the timing belt cover back off. the car started right up. the 12vdc was now back at the hall sensor connector. put the timing belt cover back on, no start. pulled the cover back off and the car started again.

i know theres not a sensor or anything down there, but whats going on here? wiring? anyone have experience with this?