I installed a evo 7 throttle body onto a 4g91 engine. The TPS socket connect directly into the evo 7 TPS but the IAC valve need some wiring as the socket is different. Done all that. Clean the throttle body too but I can't seem to get IAC Valve to work properly. It idle at 2500 RPM. I can't get it to idle lower. The BISS screw in all the way but still lock at 2500 RPM.

Have anybody got any experience performing this kind of mod?

I'm new to this forum. Hope can share some info.

 

you have a vacuum leak if your biss screw wont affect the idle. essentially its pulling air from somewhere else. also you should hear a clicking type of noise when you turn the key on and thats the iscv doing its thing, if it doesnt do that its not working at all. and also most likely wwill have to tune the ecu afterwards for the air volume difference and iscv step difference