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Idle air
The toyota iac is a two coil unit.
Can this be controlled ?
BMW and audi uses similar iac, and both are controlled. MembersPage/GergelyLezsak/IdleControl controlled it first, now the feature enabled in standard firmware.
- "Rob is banking" on the dual-solanoid IAC thing working as the whole IAC thing has caused the first 20v I did to behave very badly at idle.
- what frequency (iacpwm_speed) did you try ? (with what firmware? 00 value is very high frequency again since 1.0.43 or so, the audi valve required this).
From global.h :\n
uint8_t iac_conf; // iac, bit7:softidle bit6:asym bit5:dualsol bit4=1:ignadv ON, bit3:preciseidle bit2:stepper(0=pwm) bit1: low_power_halt bit0:power_iac_only_when_move
You need to use dual solenoid (bit5=1) with the standard PWM (precise-idle) valve settings. iac_conf=0x78 would be good, but iac_conf=0x68 is better for start (ignition-based idle off via bit4=0).
- "The needs to be to wires for it", right?
- what is the question exactly ?
- with dual solenoid output, there is some restriction with the output selection. The 2 outputs must be neighbors like configure ign/6 and use ign/6 and ign/7 (the latter will be inverted), see GenBoard/Manual/DigitalOut/Table
The IAC valve is now working, and the idle i fair, i have to let it idle at 1100-1200pm otherwise it will stall,after i let go of the gaspedal.
Complete iac config (mcd dump):\n
iac_step_seq=C9 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 launch_rpm=14 iac_integral_limit_dec=A0 iac_integral_limit_inc=FA iac_integral_deadband=FF iac_deadband=0A als_cut_maxtps=00 iac_overclose_interval=02 iac_ref_pos[0]=BF iac_ref_pos[1]=B3 iac_ref_pos[2]=A6 iac_ref_pos[3]=99 iac_ref_pos[4]=8C iac_ref_pos[5]=80 iac_ref_pos[6]=73 iac_ref_pos[7]=66 iac_ref_pos[8]=59 iac_ref_pos[9]=4D iac_sol_channel=60 iac_ign_slope=04
iac_integral_limit_dec=A0 is way too high. set it muuuch lower (05..40 is likely) to prevent negative integral windup.
Negative integral windup: when RPM is higher than target, integral goes negative; if high iac_integral_limit_dec allows it to go too negative, it requires too much time to diminish after RPM drops under target => engine stalls.
I set this number at decimal 10 in megatune, and the stumble is gone..great.now its almost like oe
now i just need to make it stabil with the freq at zero,becourse the valve is making alot of noise,and this disapir when set to zero.
- Beware, setting iac pwm to 0 will cause (new) firmware to operate the valve at very high freq. (~2kHz) which might cause it to be unresponsive to small changes. You should look for an optimum freq where valve stops resonation (oscillating internals) but still responds quickly to small (f.e. 1 step) changes.
Here is a some great artikels regading this valve: