Hi,I'm trying to get some info for a friend to figure out whats wrong with her 1986 325.It starts and runs fine sometimes and other time it hard to start and emits a lot of smoke after it starts.It also surges while driving and the idle will go up to around 1500 rpm at stops, but not all the time.She has replaced the following parts and the car passed smog recently.New idle vale control unit,o2 sensor,air flow meter,cat.conv.,and a fuel flow meter.Any help is appreicated.Thanks