I've tried searching, but I haven't found anyone that is having quite the same problem. I have a 2009 DB9 that occasionally takes quite a few tries to start. Battery tests fine, tried replacing the fob battery. Sometimes the starter will click for a few tries and then all of a sudden crank strong. Other times it will crank strong and then cut out before the car starts. I've noticed the start button is turning white when this happens. It is very inconsistent and I have not been able to see a pattern. Sometimes I need to insert the key 15 times, other times once. It really seems like it suddenly does not recognize that a key is inserted. Thanks in advance for any advice!

 

Starter solenoid is glazed from heat... it happens to all cars... daily drivers... will need a new starter....

 

Oops, didn't see your response. After spending a bit more time paying attention to patterns I really believe it is electrical. Sometimes the switch will not turn red. Even going slow with the two finger method. Is it common for the sensor or ignition "cylinder" to go on these?

 

I would strongly suggest you have your starter checked. Youre wearing down innocent parts that will cost you more if you are having to cycle the key several times just to get it to start. Should be a 1 to 1 ratio but youre adding additional wear on the key side of the problem....

When the ring lights up, you have just closed the 12v DC loop and now the solenoid which is a coil magnet attached to the starter gets hot every time it's energized because it's supposed to engage the starter and then turn the engine over... 3 seconds max that engagement.... your solenoid has gotten too hot from all the attempted starts and now its so glazed from 10x times from failed starts...

pushing the key all in - the solenoid should instantly engage the starter gears and turn the engine over. 3 seconds max...

The only other thing that comes to mind is your brake switch is tied into the start sequence as well.. its the blue plunger behind your brake pedal.