My daughter's Punto won't start when the engine is hot, but starts OK when it has cooled down. Can't get the problem diagnosed cos by the time someone turns out the engine has cooled down, so ......... and there is no fault to find.

Has anyone else had a similar problem and if so what was the cause? Or does anyone have any ideas, please.

could be iat sensor telling ecu engine is still cold so its flooding, or lambda sensor

dave said:

could be iat sensor telling ecu engine is still cold so its flooding, or lambda sensor

Click to expand...

Thanks for that - it gives me somewhere to start. The next question is how can these be tested? Will a diagnostic check only show a fault when the car won't start or will a fault show if the car seems to be running OK? Or is it just a case of replacing them and seeing if the problem goes away?

Sorry, there seems to be more than one question!!