2.8 injection problem

hi can someone give me some pointers im having trouble with my granny when i start her up regardless of weather or temprature i have to leave her running for 10-15 mins before i can touch the throttle and even then i have to slowly increase the throttle because if i dont the engine seems like it sucks in to much air and cuts out because i've only had carb models before im not sure if its just the way the injection model is or not, i've done pressure checks on the system and the mot centre says the emissions are really good for a car of that age and i was told to check each part of the system which i have done even with the ford workshop manual i have done a fuel electrical check but still no joy.

like i said i've only had 2.8 carbs and im useto getting in starting up run for a minute or two then hammering the throttle and having no proplems