Any help please, the engine will cut out when driving at any speed, this sees to be a random thing as it sometimes will not happen for many weeks then all of a sudden it will happen two or three times a week. there seems to be no consistancy to the cut out. Any offers ( NB when cut out occurs the car will immediatly re start again)

This would appear to be an intermittent electrical fault and unfortunately almost impossiple to diagnose. It could be a bad earth or poor connection almost anywhere.
Check all the earths at the top engine mounting and at the rear of the inlet manifold. These ones on the manifold in particular are related to the injection system. Check that all the fuseholder contacts for the ignition and injection are clean and free from corrosion. Similarly check the contacts to the fuel circuit relays. Check also the connections at the top of fuel tank to the pump. You could also disconnect the ECU, make sure that the pins on the plug are clean and put it back making sure that the plug is firmly seated.
Do any other circuits stop working or is it ust the engine which cuts out?

I had some more thoughts about this. Other possibilities could be the ignition switch (obvious I suppose) or the crankshaft position sensor. If the ignition switch is cutting out the charge warning light would probably light up while the car is slowing down after cutting out - a bit hard to look for while struggling with a car which is dying among traffic. The crankshaft position sensor provides the timing reference for the injection and igntion. Without it you get no spark and no injection. I recall that a year or 2 back someone on the SAABec list had a similar problem which turned out to be the crankshaft position sensor, I can't remember the details though.

thanks for your prompt reply...i am posting this message on behalf of my brother in law and i shall ask him about what you have said and get back to you