Thank you for taking the time to respond ColinBarber.
The engine ceased when it broke down just over a year ago. As a result I had to have the following replaced:
Cylinder Head complete with valves (fortunately I got a used one off ebay - and was informed that it ran 'just fine' when it was on the car it came from);
Timing Belt and Tensioner (as it was suspected that it was the tensioner that caused the problem in the first place);
Head bolts and gasket set;
Timing Belt Idler.
All of the above changes got the car running again but clearly it was misfiring, only on one cylinder it seems so it's not bad although bad enough to realise it's not running as it should and problematic enough to ignite the engine management light with the code p1346. I've had at least three different garages look at it, including the dealers, the latter charging 'silly money' and charged me for a new coil for one of the cylinders as they located a problem there. Well, still misfiring. So I replaced all the coils just in case, albeit not Delphi ones. The Camshaft position sensor has been replaced as has the vvt valve, former Delphi latter generic.
I've rectified a few advisories on the last MOT and although it's an oldie it is a fine specimen, apart from a scratch or two I hope to get rid. Wheels refurbished and customed to suit the gunmetal grey...
I'm gutted after all the time and energy spent it's still 'playing about'. I've been advised that one of the cylinders in the cylinder head could be screwed. I wish I had got it 'air tested' now before it went in. This has me wondering because the car running like a dream before it broke down.
Anyway, I was told the ECU, or wires leading from the vvt valve to the ECU are possibly at fault and resetting the ECU could clear the misfiring. Is that even so? I'm not convinced, but I'm not a mechanic.
This problem I see as having been brought on by myself. A careful driver with enough respect for the car to polish it every couple of days and driving very low mileage annually, between 3K - 4Konly. So when time came for the big service, the one which dictates to change the belts every 80K, or whatever it is or every 7 years, whatever come first. I ignored the every 7 years because I only did around 25K and the belt looked as good as new. Little did I know that the tensioner would 'mess up my programme'. Anyway, I'm where I am now for whatever reason... blah blah