My 2010 MazdaSpeed 3 (turbo charged, ~75K miles) will have difficulty starting after prolonged (>2hrs) sitting with engine off (no difference with changes in outside temperature). I would either have to crank for a very long time or crank multiple times (at least twice) before engine will turn on. No other problems (idle is smooth).
I have done simple maintenance (brand new K&N air filter, new spark plugs, new battery, MAF sensor cleaning). I took it to dealer and they have done extensive testing on fuel pump system with no luck. They recommended decarbonizing service ($150), made no difference.
Only pattern I’ve noticed is if I rev the engine before shutting off, even after sitting overnight, the engine will start right away without any problem. Modern fuel injection engine… Can’t figure it out.
I don’t know much about cars and any help would be much appreciated!