(T) Flat spot on acceleration

My uno = 1100 Fire 1996 model...

On acceleration, I appear to hit a flat spot - where the car somewhat thinks for a moment before responding to my push on the pedal.

I have done a full service; changed plugs, oil, filters, rotor arm, distro cap, tested the vacuum advance unit and secured the pipes to the carb. I cleaned out the carb with a can of carb cleaner.

CAM belt was changed earlier this year and timing set up correctly. Although I do experience hard starting - swing-swing-fire.


Is there anything else that I could check?

Any suggestions how to cure the problem?

Tried an ECU reset?

ECU / Ignition unit was replaced in January 2010 with a new one.

How does one "reset" the unit?

Take the battery leads off for a few minutes

Reconect the battery and then start the car
Let it tick over by itself without revving it at all until it warms up enough for the rad cooling fan to come on [I usually let the Rad fan kick in 2 or 3 times] then switch it off

ECU is then reset....