I have been having problems with my 2006 Quest for the past couple of weeks. The engine cranks but does not turn over. Sometimes it starts on the second try, sometimes it will not start at all after trying 6 or 7 tries. We put a gauge on the fuel system and we are getting the proper pressure (50 psi) even when it doesn't start. I am not getting a check engine light and when the car does finally start, it runs smoothly - no signs of hesitation or roughness. There does not seem to be a pattern to when the car will have a problem starting. I can go a couple of days without a problem, then it will occur again. It can happen when the car is cold, or when the car has been running and I have stopped at a store and returned while the car is still warm. Any suggestions?