Car struggles to start intermittently
 

I have a 2010 Mazda 3 2.5. I've never had any problems with the car since I bought it 5 months ago until the other day while trying to start it, it took about 8-10 seconds to crank over. Once it finally did, it idled really low for a couple seconds then went to normal idle RPM. Since this happened, it has done it 3 or 4 times but only when I try starting it after getting gas or leaving the grocery store. It runs perfectly fine and has no check engine light or stored codes. Could it be the cam position sensor or timing problem? Any thoughts?

Thanks,
Kevin

It might be caused by a number of things like a leaking fuel injector, faulty distributor cap, alternator or battery problems.