Starting with a quake

[sdb999]

87', 22re, 5spd. Engine starts quickly and immediately quakes at a very low idle, I mean everything is shaking. A second or two later it settles into its typical smooth idle at 750-800 rpm. It's so momemntary I don't have a prayer of catching it in the act. Any usual suspects to look at? Thanks.

 

[sdb999]

Seriously, No one has any idea what might cause momentary stumbling idle at start up? I'm in the rare situation where I could actually throw parts at it within reason. Perfect diagnosis isn't required. Thanks, S.