I just purchased this car it has 212K. I replaced the ignition cap and
rotor, spark plugs, fuel filters and changed the engine oil. It seems to
run a bit rough, it hunts at idle slightly.

The real problem is when I turn on the headlights, the idle jumps from
about 750 to about 2250.

I have not found any vacuum leaks (doesn't mean there isn't one)

Anyone have any idea why and how to correct the idle situation.
Thanks