2001 clk 320 hard start
 

This is the 2nd time I have had this happen, when you go to start the engine just cranks but does not start. I have sat there and cranked and cranked waiting in between. The first time several weeks ago it started after 15 minutes this time it took over a half an hour then it started. After the first time the check engine light was on but then after a few days it went off. Now it started and the check engine light is on. It is seems like it is a fuel problem, but after it starts it runs fine actually great. Any Ideas I know it is vague and could be numerous things.:confused:

You're lucky the Check Engine light came on! I get cars in my shop all the time with issues such as yours, and there aren't any fault codes. In most cases, the Crankshaft Position Sensor (CKP) is the problem, sometimes it's the Camshaft Position Sensor. The CKP usually causes problems when the engine is hot, the cam sensor can act up any time. Have the codes read. That should give you some direction as to which way to go.