The crankshaft position sensor may fail. Symptoms of this are: The engine will crank—but not start—especially when the engine is warm. The car may start again if it is left to cool off, but it may run roughly or have poor performance. Communicating these specific symptoms to your technician can save diagnostic time.Google+
Car Problem Reports
Mercedes-Benz SLK32 AMG Engine Performance Problems Due to Crankshaft Position Sensor Failure
Mercedes-Benz SLK32 AMG Problem
Average Mileage: 62,995 mi (42,000 mi - 83,990 mi)
Visitor, 2002 Mercedes-Benz SLK32 AMG, 83,990 mi
Car would turn off while idling, and restart after approx. 15 minutes. Shop diagnosed faulty crankshaft positioning sensor. Replacing now.
Visitor, 2002 Mercedes-Benz SLK32 AMG, 42,000 mi
Same issue. Won't start after turned off warm. Wait 30 mins and it starts. Replacing the fuel relay did not help the problem.