Thread: S14 zenki idling problems

I have a s14 zenki, old engine has spun bottom end so i bought another black to sr20det and put it in. First i had a really bad rattling sound so i changed the timing chain tensioner and that rattle sound was gone but now i have another rattling sound and don't know what it is and it isn't VCT. Also when i bought the car have the wires where copped, it had a haltech e8 ecu running still have the ecu but just put in a stock one for now so i know the car is running fine but when i replaced the haltech with the stock ecu the idling on the car has just gone wacko, it will idle between 900RPM-2000RPM and not sure if this is due to my IACV wires being chopped or something else, please tell me what you guys recommend for me to do

The purple plug goes to the Fast Idle Control Valve (FICV), which is basically just an ON/OFF valve. It supplies extra air during power steering input, to raise the rpm's of the engine so it doesn't stall. It is not necessary for a smooth running idle.

The brown plug goes to the Idle Air Control Valve (IACV), which is a PWM 0-100% valve. It supplies a fine amount of air to regulate the idle speed, depending ona multiitude of other parameters (engine temp, speed, rpm target etc.). It is VERY required to have a smooth running idle.

If I were you, I would fix the brown plug first.