hello,i have a 91 gt running rich,it runs fine but when i stop at a traffic light idle will drop to about 500 or 600 rpms step on gas it clears up but goes right back a few seconds later it has new plugs wires cap and button new 02 sensors new air filter new fuel pump 190 lph fuel pressure set at about 38 with engine off ,it has longtubes no smog or cats h pipe flowmaster e303 cam 76mm mass air meter for 19 lb innectors 70 mm throttle body pulleys any help is greatly appreciated