Engine won't restart once warm?

[Cyclone1]

Hi all,

My Fathers 97 Jag 4.0 Sovereign is having a few problems. From cold the car will start with no problems, but after taking the car for a drive of no more than half an hour, if he switches the engine off and then tries to restart it, it will not restart?? This doesn't happen all of the time, but is starting to gradually get worse. He then has to wait for a couple of hours before the car will restart again. He has taken the car to his local dealer, but unfortunately every time he's took it there the car has behaved perfectly!! so they are unable to diagnose the problem. They have mentioned that it may be an ECU fault / replacement. Personally I think that it may be something simpler like a short somewhere or a sensor failing......

Hope someone can help....

[Cyclone1]

IOLAIRE,

Thanks for the reply, I will try the lambda sensors and see if it's this. Which temperature sensor is it that you referred too, and approximately where is it located?

Thanks