I have an 07 Mustang v6 and sometimes when I go to start it, it won’t start just cranks over and over. The weird thing is this only happens occasionally. But i never know when it will happen so i don’t drive it as often for fear of being stranded somewhere. The are no codes coming up. No check engine light or the little wrench light. Now the only thing I have noticed is when I turn the key to the on position you can clearly hear a whirring noise from the backseat. I’m assuming this is the fuel pump kicking in. I noticed when it doesn’t make that noise is when it doesn’t start and just cranks. So is that normal? Should I be hearing it every time? I literally have to turn the key on and off until I hear the noise. Sometimes it’s over 10 times. Pretty annoying. How do I know if the fuel pump is bad? And should I just replace it?