I think you are refering to a petrol version when you mention a timing chain, there was an early fault with low tensile chain links fitted to some models which stretched, and can show up as a crank sensor fault, first change your spark plugs and air filter and put a benzine additive in to the petrol as i think you are on the E10 fuel, this can cause difficulties in starting and stalling issues. small cost improvements in servicing will help narrow down your faults before you delve deeper.