Bucking Metro

I have a 91 geo metro Fuel injected 1 liter. When I take off from a stop the car rev's up and down about four times and then goes. Seems like it has to be at low rpm to get this pulsing. With air cleanr off if I look into the TBI I can see the fuel being sprayed then it stops then starts again. Any Ideas for this problem?
thanks
Alpa