83 rx7 radiator problems please help

[DULO83Rx7]

i have an 83 Rx7 i love to death and im really trying to figure out the problem with my car.. the problem seems as if i put coolant in my radiator and cap it once i start my car the water shoots out of my radiator even with the cap on or off still shoots water out i'm very clueless as toward the problem now... i replaced the water pump gasket... i checked the radiator making sure it wasn't clogged by removing the radiator and getting a water hose putting it down the radiator making sure it flowed correctly which it did.. i re installed the radiator and it still shoots out water so i'm stuck like chuck please helppppp!!!!! anyone please... godless.