Intermittent (electrical) Fault ?

[godfrey]

I am writing in for my pal,who doesnt have a computer,but DOES have a problem with his immaculate SURF 1992 2.4 diesel. driving along, it gives a little splutter,and the engine stops.restarting the engine,sees it going agai,which may be for 5 minutes,or until the next day when it happens again.I have taken it to 5 garages,and they all say sounds like an electrical fault,but no one can find it or CURE it,can anyone help please ? Thanks