Exhaust blip and motor shake

[cmekis]

When my car is idleing the rpm will go from about 900 to 700 then the exhaust will blip and my rpm goes back to 900 then slowly go back down blip etc etc When it blips the motor will shake to the right then pop back to its resting position. My air fuel ratio will lean out to about 17 then when the exhaust blips it will go back to 16. Sometimes that cycle happens fast other times the car will idle for about 5 seconds with idle steady at 900 and air fuel steady at 16 then the idle will drop and it will blip. My afr is 14.5 when cruising and 12.5 to 13 under boost. So any ideas? Also the car will long crank if you dont feather the throttle just right as its cranking over, if that helps. All help is much appreciated.

[PapaSmurf2k3]

I wonder if your idle air control valve is messing up, or you have a fickle injector.