Car is a 91 Z28 5.7 new south Bay injectors fuel pressure regulator fuel pump Delphi new sending unit new plugs,wires cap and rotor new TPS iac coolant temp sensor on front of intake new O2 as well can't figure out this erratic idle only in gear like the car has a choppy cam in it.car also has new ecm and will occasionally run great under a load but not consistent any help would be greatly appreciated