Just sorted my m103 out after 3 years .Replaced most parts with no real change .Till the last job was replaced the engine temperature sensor . And then i replaced the valve cover seal due to an oil leak .The oil was getting on to the spark plugs and burning off. And then i did a full clean out all the rubbish in the top along with the baffle plate thats fixed to the valve cover top with three bolts .do clean out the small bore pipe on the baffle plate as you have it it off .The valve cover as 2 holes in the side one is very small if it blocks up it restricts the breathing of the engine .That and a full tank of fuel along with petrol inector cleaner, i must say this did work for me. Thats if your plugs leads and distributor along with rotor arm are all good to start with ..