thanks for your reply.in the direction of the firing order no2 is nearest the bulkhead.it is spark plug no4 as you say nearest the bulkhead compression test is very good on all cylinders supposed to be 8.5 bar warm full throttle injector plugs of all cylinders are just over 9.00 bar may because i had the block skimmed and the head once many years ago.all the electrical side is good plugs cap leads rotor faze sencor.by pulling the injector plug of on the offending cylinder it has no impreesion on the running of the engine.ive fitted four new spark plugs and three are sooted up but the offending cylinder is as shinney as when i fdirst put it on ill swop the injector around to see if ican move the problem to another cylinder theres 12v or just over to the offending injector plug. i dont suppose you no anyone with a set of yellows i could but thanks again for the reply its people like you that make tis site so good