How do I read / interpret the timing marks on my 89 420SEL, and are there any special precautions or steps to take to make sure I'm on the specified 12 degrees BTDC ?
On a side note - it pinks like the devil - not sure if it's dodgy / bad gas from certain stations or the timing or something else. Any ideas ?
Also, #4 (R/H side closest to bulkhead) spark plug is covered in crud - the space between the insulator and plug body is almost full of build-up and it's a darkish colour. The remaining seven plugs all look far more acceptable - not much in the way of deposits and all a good colour. Just put in eight new plugs and it runs better now, but I'd like to know if I'm facing bigger problems ?