I've not driven the bus now for a few weeks and so headed into the gloomy november afternoon light do give it a run through and warm the engine. Sadly - and predictably - the huge new Yuasa battery I swapped in just a few weeks ago after the old one (8 years and counting) started going low voltage on cranking - is also going low voltage. the bus wouldnt fire and after connecting in a laptop to the DTA ecu it was as i suspected, on cranking the voltage at the ecu was dropping down below 10v, effectively lobotomising the ecu. So - out with mains cables and a charger and after an hour on trickle charge and with some fiddling cleaning contacts on relays, fuses etc all was ok and it fired - nearly first time. The map in the ecu hot startes fine but is not so keen on cold starting so while i had it plugged in i added around 20% fuel in to the cold start map across the range and it seems much happier.
After a fun run around and a blast up and down the motorway everything seemed much happier - including me.
**note to self - buy one of those dashboard solar trickle chargers - a flat battery is a rookie error......