Q: will only start full throttle and will only stay running if it's full throttle rpms don't go passed 1500 and keeps fouling plugs

If the engine is equipped with a throttle body injection system, then you should disconnect both injector harnesses and then turn the engine on to see if it looks like the injectors are putting fuel into the engine or the engine will still start and run like it did before. If it is, then your pressure regulator is leaking on the throttle body if you do not see the fuel injectors leaking fuel. The injector seal o-rings should be replaced if you see fuel coming from the injectors with them disconnected. The most common cause is the fuel pressure regulator diaphragm leaking fuel and needing replacement. If you want to have this looked at, a certified technician from YourMechanic can come to your car’s location to diagnose your car’s starting issue and let you know what repairs to proceed with.