Date registered: Dec 2005
Vehicle: 222.132 & 221.122 & 212.025 & 906.633
Mentioned: 3 Post(s)
Quoted: 32 Post(s)
Can you clarify, when you say it does not start, do you mean it does not even crank or do you mean it cranks but does not fire?
For the latter it sounds like the crankshaft position sensor. Usually it is worse with hot engine and starts to work once the engine/sensor cools a bit.
Of course it could be fuel injection but if it starts when you leave it for 10 minutes, sounds less of a fuel issue.
This must be a W203 car, you might find more info/advice from the model specific forum.