had this problem couple of times where a relay above the fuse box is faulty or has dust in it. You will have to pull the lower dash cover, the one round the steering colum so you can get a good view of the fuse box. It's the top relay above the fuse box which you cant see until you hav taken the this panel off. You can just feel it with just the little fuse box cover off but cant get to it properly. remove this relay (pain in the arse because it has this stupid clip holding it in) and spray it out with contact cleaner. This relay powers up the computer of some sought. Had it happen to a TD42Ti and it lost its glow circuit, tacho, and knocked like crazy when cold because it lost the electronic advance mechanism on the injector pump. Same thing with ZD30 engine only it needs the computer to start. Tell tail signs of this relay being dodgy would hav been that on a cold morning you would hav only seen the glow light come on for a split second and would have been hard to start. This customer said that sometimes they would reverse out of the drive way and it would stall on some occasions and been even harder to start. On this occasion it was the actual relay faulty. Just tapped the relay with a screw driver and it switched. Most other times its just a matter of cleaning out the dust and it was all good, but these were mine vehicles operating in iron ore dust every day! even just try giving this relay a tap with screw driver first. Hope this helps. Part No for relay is 25230-79981. Costs a rediculous $100 or something like that from memory! let us no how you go!!