Intermittent Engine Running Issue

[impne 2]

I've had my 89 1.9 for about 9 months, not used it much to be honest but now and again it runs rough.

 

Had it out last week and it drove really well.

 

Sometimes however it runs like its missing. Now and again on start up sometimes running down a road, all is well then it happens out of the blue.

 

It basically sounds like its running without one cylinder, revs jump up and down, it cuts out, you feather the throttle to try and keep it going but it bogs down.

 

It did it when I first bought it, checked alternator and it was pulling 12 so changed it and charging well now, thought at first it was just that but obviously not.

 

It isn't used that often but neither are my Visa's and they run fine so must be something else.

 

Thought I'd ask if it was a common problem anyone was aware of?

 

I do mess with my cars a bit but not trained mechanic