hey i have a 1993 corsa gsi with a c20xe in it and have owned it for a few months, it missfired slightly when i bought it and that was the only apparent mechanical fault, but recenlty when it comes to switching the engine off it will turn off as normal for a second but then its like it tick over once more or just trys to fire up once more.. could this be from low petrol as i have just flushed the radiator out over two days and the engine been running on really low fuel, any help at all is much appreciated thanks loooooads!