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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: = Idle Air Control = Full details on the types of Toyota IACVs can be found here: http://www.autoshop101.com/forms/h60.pdf == Stepper ISCV == http://www.cygnusx1.net/Supra/Library/TSRM/MK3/FI/FI_106.gif http://www.cygnusx1.net/Supra/Library/TSRM/MK3/FI/FI_107.gif == Two coil ISCV == The early type is a simple solanoid, called a Vacuum Switching Valve, which allows a vaccum to pass to a set of bellows that move against the throttle plate stop. They are triggered by ECU, or various electrical load switches. Most people remove these when going to a stand-alone system, as they do not work very well after 25years of service. The newer 20v engines have a Dual-Control Rotary Solanoid IAC System, marked as A on the picture below. http://vems.hu/www.vems.co.uk/VEMSInstalls/4AQuestion.jpg One coil opens the IAC valve, the other closes it, with neither coil active the IAC valve sits at 50%. The document states: ''The ECM controls IACV positioning by applying a duty cycled signal to the two electrical coils in the IACV. By changing the duty ratio (on time versus off time), a change in the magnetic field causes the valve to rotate. Basically, as duty ratio drops belpw 50%, the valve closes the passage. If the IACV is disconnected or inoperative, the valve will move to a default position and idle rpm will be around 1000 to 1200rpm at operating temperature.'' == The Solution == Thanks to the new Dual IAC firmware (1.0.30 on) and MembersPage/Skassa the Dual-Control Rotary Solanoid is now controlled correctly by VEMS. The following config values were used: <code> iac_conf=78 iac_max_steps=FF iac_tps_thres=08 iac_cold_idle_temp=A2 iac_warm_idle_temp=B4 iac_cold_rpm=96 iac_warm_rpm=82 iac_cold_start_pos=80 iac_warm_start_pos=66 iac_afterstart_rpm=23 iac_afterstart_duration=A0 iac_speed=06 iac_kp=6E iac_ki=03 iac_kd=FF </code> Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.