PLEEZE HELP!!!!! Engine Troubles

Hey guys,
my name is josh and i own a 1991 EA series 2 falcon and hav been having a bit of trouble lately with my belovered blue oval. The car has been stalling, both driving and sitting at the lights. When u try to start the car after stalling, it wont start staright away and u have to leave the car a while bfor trying to start the car again and it will start. the car is also delaying for like half secnd from take off. I dont know wat the cause is. Ive just put in a new pod filter, spark plugs are only 6 months old, the car is hardly driven hard, i run it on BP ultimate (98 ron), the throttle body and injectors hav recently been cleaned and a new started motor has been put in about 6 months ago. U MUST HELP ME!!! im so so so tempted to buy a new car bcoz of this problem, its that annoying and embarrasing. i was thinking the problem is either the air fule ratio, spark plugs, fuel filter or ecu problems.
A relpy by anyone would b awesome,
email me on fordfan_josh27@hotmail.com or just reply to the thread,
cheers boys
Josh