Mitsubishi L200 wont start

last week in the mornings car would use most of battery to start, then 5 days later needed jump start in the mornings (started and runs fine after that) and the last day needed a tow but would start withing 20 yards afther that it would hardly take the trotle but would tick over no problem (no engine ligt comes on).... have changed fuel lift pump but no change. any idea of what to do next( to me it felt like the fuel was draining back to the tank over night but cant see how........help