Idle control valves... types?

[The Witzl]

Interesting..... perhaps I should pull one of the 20V ISCV's that i have apart and find out

good thing i have a spare

[3t-RA40]

... i thought the 20V one is a 3-wire "push/pull" type, as opposed to the simple 2-wire open/close PWM type that the XF falcoon has.... ?

I'll post a piccie up of the two side by side tonight


They are most definitely boost friendly, blacksupra's MZ21 uses one that I pinched from piccies for him, and is run off his Autronic.

I too am going to be using one on my 18R-GTE. I've got about 3 of the things sitting at home... i make sure to collect one from Piccies everytime i visit

Thanks for the info. Might have to try one of these as I don't think the Haltech is control my factory 3T one correctly.
Cheers,
Neil.

[The Witzl]

Niel,

the factory 3T idle speed motor is a simple on/off device that's controlled by temperature. In the factory setup, it gets power from the circ. opening relay (fuel pump relay) and is earthed to the manifold. When it's below 60degC, it allows air through... and closes up above 60degC.

Its the same as the 2T-GEU, 18R-GEU, 5M-E, and similar aged motors.

[brett_celicacoupe]

could always make up a flange to fit the 7mge/1ggte ISCV stepper motor

[CrUZida]

1UZ nonVVTi has a removable flange.

[Norbie]

This XF contraption looks perfect for my 18R-GEU. Has anyone tried controlling one of these (or a similar device) with a Haltech?

[The Witzl]

This XF contraption looks perfect for my 18R-GEU. Has anyone tried controlling one of these (or a similar device) with a Haltech?

Probably lots of people. Considering the Haltech has a PWM output for the ISCV (from your email), then it will work perfectly.

Same as it would for any programmable ECU with a PWM output for idle control.

[The Witzl]

could always make up a flange to fit the 7mge/1ggte ISCV stepper motor

Brett,

problem with that is that most aftermarket ECUs have a PWM output for idle control, not stepper motor control. It takes anywhere from 4-6 wires to control a stepper motor, but only 2 to control a PWM valve.

PWM is a lot easier to control and design into a circuit, and is a more versatile output in terms of useability, so is the preferred choice of an ECU designer.
PWM is also a lot more accurate to tune with, since you have a 0-100% range, rather than a couple of steps.

[brett_celicacoupe]

Brett,

problem with that is that most aftermarket ECUs have a PWM output for idle control, not stepper motor control. It takes anywhere from 4-6 wires to control a stepper motor, but only 2 to control a PWM valve.

PWM is a lot easier to control and design into a circuit, and is a more versatile output in terms of useability, so is the preferred choice of an ECU designer.
PWM is also a lot more accurate to tune with, since you have a 0-100% range, rather than a couple of steps.

solution; http://au.farnell.com/jsp/endecaSear...sp?SKU=1094209


and, couple of steps?!?!?!

one step on those stepper motors is like 1degree.... multiply that by the pitch of the thread of the valve and you have how much the vlave closes.

and i think a stepper motor ISVC is more verstile than a PWM open/closed valve. i doubt the PW/air flow is very linear

[thechuckster]

there's guys/girls using PWM driven idle valves on megasquirt-driven engines - you can even have rudimentary target tables for temp depending on particular version of tuning code.

i like the idea of PWM driven is that the feedback is from the engine (e.g. existing sensors) as opposed to the stepper motor feedback (yet more sensor input/handling).

[ed]

the new wolf can do x8 channel 3D PWM mapping with a further 2D overlay...

i think that can handle my idle

[JustCallMeOrlando]

problem with that is that most aftermarket ECUs have a PWM output for idle control, not stepper motor control. It takes anywhere from 4-6 wires to control a stepper motor, but only 2 to control a PWM valve.

It only takes 4 to control the stepper, the other 2 are power. FWIW, I decided to retain the stepper with my setup because a) I wanted a factory look, b) the Adaptronic could do it and I had enough outputs and c) I figured if Toyota still use it in this day and age of uber emissions, it must be a good thing.

[The Witzl]

It only takes 4 to control the stepper, the other 2 are power. FWIW, I decided to retain the stepper with my setup because a) I wanted a factory look, b) the Adaptronic could do it and I had enough outputs and c) I figured if Toyota still use it in this day and age of uber emissions, it must be a good thing.

Well the in reality, a PWM idle valve only requires one wire from the ECU to control it, the other one is power

It's all up to what suits you and what you are happy with. I like the PWM types because of their flexibility between different ECUs and adaptability to virtually any engine. Being that the 18R-GE doesnt have much of a ISCV (it has an external AUX AIR VALVE like what's on a 4A-GE throttle body), i see this as a big improvement, with only small space useage.

[JustCallMeOrlando]

Indeed. Definetly a good thing being so simple. I was going to use a 20V one for the same reason when I was going to use a Microtech.

[brett_celicacoupe]

I like the PWM types because of their flexibility between different ECUs and adaptability to virtually any engine.

stepper motors are driven by PWM. its just 4 phase uni-polar PWM