Idle hunt, running lean, humming noise from aem intake

bear2230 · Postby **bear2230** » Fri Sep 12, 2014 9:05 pm

Teach us Greg, you are ECU Yoda. Thank you for your input. You make this forum a richer place. Well done.
I think that's two people I've complimented now in the last 6 months……Must e a leap year. :lol:

Richard.

gslender · Postby **gslender** » Fri Sep 12, 2014 10:08 pm

Lol.... I guess G could be anything, but for me, it stands for Grant.

Lokiel · Postby **Lokiel** » Fri Sep 12, 2014 11:02 pm

gslender wrote:Lol.... I guess G could be anything, but for me, it stands for Grant.

Not MegaSquirt "Guru"?

bear2230 · Postby **bear2230** » Fri Sep 12, 2014 11:07 pm

gslender wrote:Lol.... I guess G could be anything, but for me, it stands for Grant.

Well sorry about that Grant. I think that puts me back to only one person this year so everything in the universe is back in balance.

mrbrossnan · Postby **mrbrossnan** » Sat Sep 13, 2014 7:16 pm

Thanks for all the inputs guys!

Gslender, so this is what mine is set to:
max value is set to 100% and step period to 11ms. the lowest setting for the step period is 5ms.
do you suggest me changing that to 5ms?

gslender wrote:
david_syd_au wrote:I think the "step period" of 5mS is what sets the frequency, 200Hz in that case, and the duty cycle then varies the ratio of on/off signal to the ICV motor at that frequency.
If you were to reduce the step period to say 2mS, then the control frequency would be increased to 500Hz, and MAYBE making the hum less audible.
My NB8A has a megasquirt with the control frequency set to 480Hz, and there is still a noise, but it is not audible when the motor is running.
I know SFA about adaptronic ECUs, so you should consider consulting an adaptronic expert (aka Andy) before making such a change.

Unsure given I can't be certain where in the Adaptronic ECU it defines the PWM frequency. It does seem likely that Step period is the right setting and I agree with David's explanation that setting it to 2ms would be the correct frequency for a MX5 idle valve. I'd suggest changing it to 2ms and see if it improves the idle and noise.

G

Lokiel · Postby **Lokiel** » Sat Sep 13, 2014 8:49 pm

^
Not applicable to MX5's, we have a PWM Idle Control Solenoid (ICS), NOT a stepper motor, for Idle control.

In WARI, select AuxOut Tab -> AuxOutputNumber:1-HighCurrent(3A),PWMcapable, then consider changing the "Frequency" field value from "500Hz" to "1kHz".

gslender · Postby **gslender** » Sat Sep 13, 2014 10:11 pm

Lokiel wrote:^
Not applicable to MX5's, we have a PWM Idle Control Solenoid (ICS), NOT a stepper motor, for Idle control.

In WARI, select AuxOut Tab -> AuxOutputNumber:1-HighCurrent(3A),PWMcapable, then consider changing the "Frequency" field value from "500Hz" to "1kHz".

Thanks Lokiel, that makes sense. I was wondering why the software screen in the Adaptronic was talking about stepper - but didn't know where in the software you'd specifiy the Frequency. I'd actually think 500Hz would be fine as is (but perhaps a little low... I think it needs to be 600Hz) and that 1kHz would be too much. Is yours set to 1kHz ???

G

Lokiel · Postby **Lokiel** » Sat Sep 13, 2014 11:13 pm

gslender wrote:
Lokiel wrote:^
Not applicable to MX5's, we have a PWM Idle Control Solenoid (ICS), NOT a stepper motor, for Idle control.

In WARI, select AuxOut Tab -> AuxOutputNumber:1-HighCurrent(3A),PWMcapable, then consider changing the "Frequency" field value from "500Hz" to "1kHz".

Thanks Lokiel, that makes sense. I was wondering why the software screen in the Adaptronic was talking about stepper - but didn't know where in the software you'd specifiy the Frequency. I'd actually think 500Hz would be fine as is (but perhaps a little low... I think it needs to be 600Hz) and that 1kHz would be too much. Is yours set to 1kHz ???

G

Mine's at 500Hz and I suspect that's what most MX5 Adaptronic users use (I think the OEM ECU uses 450Hz).
The selectable Frequencies are 25, 50, 100, 200, 250, 500, 1000, 2000, 23000, and 128000Hz.