Well (touch wood) my problems are now fixed. The removing power from the ECU had no effect so as a last attempt I thought I would buy a product I saw on QVC.
Yeah I know its normally a joke to buy from a shopping channel, but I paid extra for next day delivery and put the two bottles in the fuel tank and one in the oil and after a five minute drive the juddering stopped.
This morning my car even started first turn of the key, so like I say fingers crossed I can now enjoy my Punto.
The product is called Asta 3000 and is exclusive (aparantly) to QVC and can be found at:
Good stuff that. If your engine's not been given the 'red carpet' treatment in its life then this stuff will make a noticeable difference.
Some people use sh*t oil and petrol and after a while the system needs a bit of a clean out. And this kind of thing can help.
I pop some Redex into the tank every now and then and fill up with BP Ultimate or Shell Optimax occasionally. Plus I use Mobil 1 Supersyn oil and Fram Oil Filters which have always kept my cars happy.