ok so recently my engine lost compression in 3 cylinders resulting is this im told its bad detenation, now i didnt realise i was running pretty leav for months on end due the the fuel pump gradually dying on me and its only when i went to performance hq to get the map checked as it felt flat russ told me it was about 15 afr at 4000rpm so we eventually changed the fuel pump and it ran fantastic for about 200 miles and then i felt as though it was loosing some power (a thread is in the engine bit). so the engine has been stripped and my engine guy reckons it may be down to the injectors as its only 3 which are really bad and one is fine with just a few score marks on the side. he also suggested the dastek unit i have could have caused this, but its been on the car for a few years now so not sure.. ive ordered new pistons, rings, shells etc but not sure what to do about the injectors as im only running a hybrid setup at the moment and he said i'll need to get the map altered if i changed to bigger injectors. whats your thoughts ?