2012 GT struggling on cold start.
Every once in awhile my mustang, with 45K miles, has trouble cranking. The symptoms include a longer crank duration than my normal and more common ones. After it does crank, the RPM needle shakes rapidly below 0 RPMs before going up to normal crank range. This has occurred on both level and angled ground. I have had more than a half a tank of gas during all but one occurrence. With 45K miles I'm wondering if there is a component i should replace or upgrade? I bought her with 41K. It also seems to be happening more often lately as well. ANY help is much appreciated. Thanks you.