Megane 1.6 Fuel Filter

Hi, wife's 2000 Megane 1.6 (K4M) has for a little while suffered from a sporadic loss of power under load. However it has mostly been running OK and idling OK and starting first time on the key. She has complained in recent weeks that it has been getting worse. I have renewed the throttle body o-rings.



However it has now developed to a point a where it won't start unless you pump the gas, and even then will only keep running if you keep your foot half down (3000 rpm). This latest development in the last 24 hours.



I suspect a possible clogged fuel filter and intend to change this first as it's cheap and it's never been done as far as I know.



Any pointers please ? Haynes book has all sorts of warnings about depressurising, do I need to worry ? (I disconnected the electrics to the fuel pump last night).



I wanted to take a look in the fuel tank but can't seem to shift the fuel pump locking ring.



Thanks