Starting Idle Question

I have a '92 LS - just purchased it about four months ago. She had 213,000 when I bought her, and I have replaced a few itmes already, brakes, calipers, filters, etc. She has the typical subaru main seal leak, which really isn't the concern to me except for the oil "blowback" onto the exhaust systm, but that is not the reason for my post.

When I start the car in the morning the Idle rev's high, low, high, low very quickly, unitl I hit the gas pedal and the idle smooths out.

Has anyone else experienced something like this? and could it be a PVC valve issue, fuel filter issue??? Any input would be greatly appreciated.

Thanks!

Oh, she now has 227,000 miles on her and I love the car!