I have a 2007 murano sl... 72k... when I first start it in the morning it has a hard time turning over for a few seconds and then once it does, the rpms shoot way up then back down to normal almost like I'm flooring the gas pedal but I'm not touching it at all.. it only does this on the first start of the day. I can start it after that and its fine... any ideas on where to start? ​​​​we did just replace both cam shaft sensors... maybe that might have something to do with it?