car cutting out

Hi to all
wondering whether if anyone could help me on a little problem with my rover 620 si cutting out while changing through the gears while driving.started about a week ago when starting the car up everything fine,then when switching off engine and restarting it would not start for about 2 to 3 mins. put it down to maybe dampness or cold.but now i am experiencing the car jumping while driving as if it is starved of petrol or auto choke is sticking.yesterday,going round a roundabout i went up into 2 gear on to third and the engine just died,had my foot on the accelerator but nothing just cut out.this happened another 2 times after.it does not always happen,but any info would be much appreciated as iam at aloss at what it could be.
many thanks in advance.

When was it last serviced? What's the condition of the dizzy cap and rotor arm? I've heard similar but not exact reports and it appeared to be old/faulty parts