Rav 4 engine turning over but won't start

Look at the electrical connections and clean them. ( I know it's no it time consuming but...) Start with the battery cables clean and retighten them check the ground (negative wire to see if the attachment to the engine block is clean and tight, same with the positive (+) wire. look for any frayed or broken wires. Look for any cracked or broken vacuum hosed replace if found (auto parts store will have hose in amount you need) This may not be the solution either ; As tennisshoes says intermittent problems a hard to find. Good Luck.