Defender 90 flooding at startup

I have a 94 D90 and if it sits for about 4-5 hours it will not start. After changing the wires ,plugs, cap and rotor changed fuel pump, got to diagnostic box and found no codes , check engine light is not activated then I pulled the new plugs and they were black and smelled of gas so the engine is flooding, if you hold the accelerator to the floor it will eventually crank and idle good. Cleaned the IACV and no help funny thing is if I remove the electrical connection from the IACV with the engine running the engine is not affected nor does the check engine light come on. After initial startup it will crank back up ad run seemingly normal as long as you crank it before it sits too long. Any help?