My car will not start. Did go but was left out side with lights or something on flattened battery. Put new battery on but still nothing,thought it had lost code so have had key recoded. Turns over OK but nothing happens my just fire sometimes as though it wants to go,but no luck have looked at the plugs while turning over and noticed an occasional spark. Have replaced all sensors when scaned shoes no faults. Garage said timing chain needs replacing but it was running. Would this cause the engine to stop just like that ?