IT only runs on four cylinders on 1994 Mercedes-Benz SL500

Mr car will only run on four cylinders,I have replaced both coils and checked the distributors but It still wont run on all eight cylinders...any advice

1 answer
check the timing,if one of the chain rail breaks the chain will jump a cog on the chain sprocket,this will usually be on the drivers side. you can check by pulling wires on either side.