Won't start when Hot!

Hi, I've got a 99 model V6 with the ACK engine. Having problems starting the car with a hot engine. All ignition lights function correctly, the engine spins over freely, but fails to fire. it appears that fuel is getting through OK as this can be smelt through the oil cap after attempted cranking. Allow it to cool down slightly and it fires on the first turn of the key and will run for hours at high speed with no hesitation. Could anyone help or shed any ideas. If so it would be much appreciated.

sounds like a faulty coolant temperature sensor. If the sensor is telling the engine its -250deg f when its really 195deg f than its going to pour in un-needed fuel and the car wont start. Has the coolant guage randomly went to full hot or full cold when driving? this would indicate faulty coolant temp sensor. Its a common failure.