Hello all,
just spent all day under the bonnet checking out the bits you all suggested.Could not find any loose or faulty wires, connections or anything out of the ordinary.Took it for a 40 mile run with my friend following (with the tow rope) just in case. Sods law it ran perfectly.
What I have just discovered 1/2 an hour ago when I decided to check the earth on the ECU (after finally gaining access) was that the "plenum chamber" (I think it is called) in which the ECU is housed, had about 3 to 4 inches of water in it as the drain hole was blocked solid. I have now cleared the blockage and am about to get the hair dryer in to dry things out a bit. I have no idea if this will solve the prob or if it has done any damage, only time will tell but I would urge you all to check yours NOW as I think this could prove to be very be expensive. I hope this will be of some use to someone.
I am most grateful to all who replied to my post, this is a great site. Thank you. Will report back in a while and let you know if this has solved the prob.Take care, and get your drains cleared !!!