Acceleration Lag - 89 190E 2.6

My car has recently developed an attitude. When I first start it, it lags and hestitates in acceleration. It's almost rythmic! And the transmission seems to be "popping" into gear with hard jerks.

I've changed the plugs (copper), checked the wires, dist. cap and transmission fuild level. All is good.

Could this be the result of the ealier problem I inquired about over the w/e (Low radiator fluid level)?

Thanks for any advise.