wan

Hi as a new member I would like to say hello and hope that someone can give me some advice on my troublesome lupo. I have the 1.4 on a 52 plate and it will start first time every time when cold ,but once started and run up to temp then stopped for any time exceeding about 15 mins the little devil will not start. If you crank the engine and pump the throttle it eventually starts . There is a strong smell of petrol and car runs lumpy untill you get it to rev then its ok until its stopped again .It will start again ok if you try straight away . I have had it on numerous conputers but all come up with no fault .I have been advised to change the mass air sensor or clean the throttle body .Has anyone else had this trouble or am i the only lucky one. Any advice gratefully accepted