1988 560 SL low milege, is having a problem sometimes when you start the car the ABS light is on, when this light is on it takes longer for the car to start and when it does start it idles very high. You can turn it off and start it again and it will fire right up and idle just perfect and the ABS light will not be on. It comes and goes where it idles funny but whenever it does happen the ABS light is always on. Any idea what could tie this all together? Thanks