My Ford Ranger pick up double cab keeps on cranking but not starting. I changer air filter, oil filter and poured new oil, but unfortunately nothing works

Started off wouldn't start hot now just won't start drained and cleaned tank changed filter getting fuel to filter ?

Sometimes it's start in the morning but after driving for about ten km if you stop and turn it off the ignition and try to start again doesn't start until I spray the quick start in the air filter the… 

Two days ago I backed the p/u in the garage, it was running fine. The next morning it cranked and cranked but wouldn't start. Never had this problem before.

Had a flat battery last week, had to use another car to work, came home and got nrma to jump start it as battery was completely dead by then. Filled up the tank and it felt heavier than usual. Headed…