Peugeot 309 cutting out on starting (cold only)

Car cut's out when starting from cold unless accel' pedal is depressed. It has to be revved up for about 30 seconds or so. After starting sometimes it seems to flood an odd time before it reaches normal running temp.
The odd time it will cut out at traffic lights or if left to idle for a long period.
Have cleaned throttle body housing and fitted new stepper motor,engine temp sensor and air temp sensor. Checked all wiring connections. Car doe's not lack power or any other symptoms and has been serviced recently.
Any ideas ?