Hi, my 97 auto has a very bad tickover when warm nearly stalling and a misfire on a steady light throttle. Under load it's fine and starts instantly hot or cold. It's not overheating and sounds ok. I've just bought it and it had been unused with nearly no diesel in for a few months, parked on a steep driveway. It seems to be worse if I go up any inclines off road. Any ideas guys?