hi guys ,i have a blue 13bt which ive had in a couple of 40 series over last 25 years , engine hasnt done lot -200k , was at tropical sea level for most and now at 800-1500m asl ,ive noticed over time on cold startup (with idle set around 750/800 when warm )idle is too low and stalls and have to use hand throttle until warm ?bit of a pain if others drive it ! any help much apreciated -p.s has no air con or other auxillary gear cheers