Iv'e just aquired a 2ltr petrol focus ghia auto, when starting there is a loud whine from the engine, gets quieter as it heats up, then when I switch off the whine carrie's on for a few seconds on it's own. Also when starting it now and then seems to only fire on about two, all I can do is switch off and start again, often when accelerating the take up is very jerky, but not all the time. ? Ta. RN