Hi. I've got a 1992 sl (300 24). Every so often the ABS warning light comes on. Every time this happens the MPG gauge starts reading incorrectly. When the warning light comes on the car will be difficult to start when cold and it will take some 30 seconds before it builds up enough revs to move. The warning light only comes on at the beginning of a journey - it never comes on when the car has already started. This happens for a few days, gradually getting worse then it goes away for a bit. I believe that all these problems are somehow linked. Any ideas please before I take it to a Merc specialist?

Thanks