Ok..so this afternoon I replaced the spark plugs/wires/cap/rotor and the valve cover gasket (full kit).

Everything went well....it runs better except that when the car is in park, the idle jumps to about 1500rpm then drops to 1000rpm then back to 1500 etc etc.

Is there a sensor I need to swap out on it?

 

I just wrote up something in DIY about setting "base idle".

 

Sweet! I will go and read it.