I drove to work this morning and as was about to park, my car just died. I re-started and it started fine. I switched it off and restarted again, taking my foot off the petrol, it just died. It does not want tto idle. We checked the petrol pump and filter, checked the idle screw, checked spark plugs and everything is fine. I'm starting a new job in less than 2 weeks and can't afford to be without my car. I need urgent help, please! What could the cause be for my car not to idle?