it sounds like your throttle valve might need a clean. it is a comman fault on the 1.4 engines if you take the throttle boady off and turn it upside down you should find ther is a carbon build up (its black no the butterfly) this build up gives the ecu the wrong signals and gives it the wrong amount of fuel. take off the throttle boady and clean it with carb cleaner make sure there is no trace of carbon. when you first try to start it it might missfire and smell dont worry that is just the carb cleaner. if that does not solve it you could have a fault with you coolant temp sensor. hope that helps you.