Slugish and over rev's

I have a 145 1.8 16V. Since I’ve had it, I’ve found it to be sluggish when it starts from cold and after it’s been running for a while and gets to normal running temp. I’ve just had a full service but the problem still hasn't been resolved any ideas anyone? Does the ECU need checking or what? Could it be a fuel blockage? Help from anyone would greatly appreciated.