i have a 87 k5 blazer with a 350tbi if im giving it gas it runs fine but in idel or when i take my foot off the gas and coast it spatters like it wants to stall and some times when i back up or stop it will stall ive changed the coolent sensor, tps, map sensor ,fuel filter ,plugs and wires and cleaned my injectors can any one point me in the right spot?

 

Check the idle air control on the side of the TB.