Thats right if the fuel control is doing what it should be & 4 injectors are not squirting fuel it would sense lean & add fuel if they are squirting & no spark meaning the fuel is not being burnt then it should sense rich & lean out to compensate probably not enough run time to burn the fouled plugs clean i have seen compression drop up to 30 psi on a wet cylinder wall recovered when running properly check your oil to see if it smells of petrol