Mazda Protege / Protege5 / MSP with FS-DE 2.0L Stock Idle Valve / Solenoid Control

[mazda_sp20]

Hi Guys,

I used a standalone EMS ecu to control my fs-de fuel and ignition and use the factory ecu to control the rest of the car.

The factory ecu handling the idle control works well, but could be better, as it tends to hunt in different temperatures and environments.

Only today I disconnected the factory ecu from the Idle Solenoid and wired it to my aftermarket EMS ecu.

I noticed the guys using megasquirt are using 55Hz PWM to control the idle solenoid

This works for me, but the valve and intake is so noisy with these settings.

I have set up at the moment using a base PWM 71hz

Everyone else's thoughts

 

[br289165]

Can't you disconnect the IAC valve and set the idle off the throttle screw, then adjust (add at lower temps with a little more timing) )fuel on the temp screens to smooth out idle?

 

[Maxx Mazda]

I used to run the stock BACV off my Haltech. Used about 80ms iirc.

Switched to the stepper motor idle control in the stock housing ( see my build thread) now.

 

[br289165]

I'm not up on the acronyms, whats BACV and iirc? I'm runnin a Microtech anyways.

I used to run the stock BACV off my Haltech. Used about 80ms iirc.

Switched to the stepper motor idle control in the stock housing ( see my build thread) now.

 

[Maxx Mazda]

Bypass Air Control Valve (it's the term used for a solenoid based IAC valve) and iirc means if i remember correctly.

 

[mazda_sp20]

I used to run the stock BACV off my Haltech. Used about 80ms iirc.

Switched to the stepper motor idle control in the stock housing ( see my build thread) now.

I have checked out your thread, very impressive.

I will have to goto my local wrecker and find this stepper motor from a Holden Commodore (GM).

Was it removed from a V6 or V8 GM?

this is the picture taken from your thread

 

[Maxx Mazda]

I have checked out your thread, very impressive.

I will have to goto my local wrecker and find this stepper motor from a Holden Commodore (GM).

Was it removed from a V6 or V8 GM?

this is the picture taken from your thread

I pulled it from a Pontiac Grand Prix GTP. They're literally on EVERYTHING GM made though. The commodore should have one.

 

[coyotanark]

Hi. I had a similar problem and a friend with his stock car saved my life, he put the scope on his to see how the stock ECU handle the valve. Now it's working perfectly in PWM warmup mode, the valve doesn't make any strange noise and acts like she have to.


This the scope, it's commented in French but that's simple:
- froid = with engine cold
- chaud = with engine hot
- chaud + ventilation = with engine hot and heater
- chaud + ventilation + phares = with engine hot and heater and headlight
- frquences = frequencies
- rapport cyclique = duty cycle
As you can see the valve works between 400 and 500 Hz. I set mine at 440Hz fixed, and with 70% in PWM it's nearly closed and I'm at 700RPM, and with 50% it's not wide open, I can set it lower but I'm at 1600RPM with 50%, which is far enough for any idling situation.