IAC valve options

Specifications, applications, part numbers, and prices for various OEM fuel injection components.

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Subaru_EA82_4EAT_AWD
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IAC valve options

Post by Subaru_EA82_4EAT_AWD »

Hi, I'm trying to get my build shopping list together and would love your input on PWM or stepper IAC's that MS3 + MS3X (not pro) can trigger.
...Something that can be bolted on a custom plate with ports and barbs, I like the look of the Ford type valves with the 'diamond' shaped flange, that can be mounted with 2 bolts on a custom plate remotely,

Any input on types of valves and people's success with getting them to work or even settings would be great...

Something available locally on the Australian market would be preferred but not essential

Thanks.
Last edited by Subaru_EA82_4EAT_AWD on Thu Mar 17, 2016 3:25 am, edited 1 time in total.
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
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Subaru_EA82_4EAT_AWD
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IAC valve options

Post by Subaru_EA82_4EAT_AWD »

Well, Ive bought an MS3 + MS3X, it on it way so I need to start nailing some parts down...

Whats everyones thoughts on preferred type of valve (pwm or stepper)?

I will be using it on a 1800cc engine.

thanks.
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
Matt Cramer
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Re: IAC valve options

Post by Matt Cramer »

VW and BMW cars from the '90s typically have PWM IAC valves with convenient hose barb fittings.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Subaru_EA82_4EAT_AWD
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Re: IAC valve options

Post by Subaru_EA82_4EAT_AWD »

Do you think pwm valves have an advantage over a stepper?

If so, is the bosch valve the best to use (I.E. over the ford diamond flange valve) and are settings readily available?
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
Matt Cramer
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Re: IAC valve options

Post by Matt Cramer »

Since you're looking for something with barbed fittings, yes - the PWM valves actually come in a ready to run version with barbed fittings. For a stepper, you'd need to use something like our remote mount IAC body.
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Subaru_EA82_4EAT_AWD
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Re: IAC valve options

Post by Subaru_EA82_4EAT_AWD »

I'm not actually concerned with if it has hose barbs or not, i can always machine-up an adapter plate (the reason I was looking at the Ford bolt-on valves) or buy the jeep adapter DIY sell, I am more interested in getting the best type of valve and easiest to set up...
I realise that the term 'best' is relative but I need to invest in an IAC valve, so I may as well get a proven type, that works well and is well supported on these forums if I need help tuning it.

Good Idle control is the main reason I'm going to an aftermarket ECU, nothing annoys me more than pulling-up and my idle being high or low - that probably sounds ridiculous to some, but that's just how I am!

I would assume the Jeep valve would fit the above description as it is sold by DIY, therefore recommended?

I am very open to opinion, though, especially experiences of PWM vs Stepper

Arent the barbs on the bosch iac's quite large anyway? I will be using 1/2" hose

Thankyou very much for your help too, I do appreciate it!
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
nathaninwa
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Re: IAC valve options

Post by nathaninwa »

After tuning both stepper and pwm, I much prefer the ford pwm and install on all my installations
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slow_hemi6
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Re: IAC valve options

Post by slow_hemi6 »

The valves from a late 90's hyundai accent seem popular and very easy to get in Australia. Same design as bosch I think.
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Re: IAC valve options

Post by Subaru_EA82_4EAT_AWD »

nathaninwa wrote:After tuning both stepper and pwm, I much prefer the ford pwm and install on all my installations
...thankyou for the feedback. May I ask for more details on your findings?
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
nathaninwa
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Re: IAC valve options

Post by nathaninwa »

The stepper motor programming is weird. When in open loop warm up mode, stepper position is based on coolant temp. If when hot, I command new steps, no matter the range the idle steps won't change, until something happens to coolant temp. Hard to type till you try it yourself. And when I closed loop and using idle timing correction, on 3 LS based setups now the stepper position is never predictable. Say at one moment it's idling at 80 steps, blip the throttle or go for a drive and now it's idling at 150 steps, with timing being different. Not a big deal right, till you try and setup the initial value table based on air temp and the times it wants to use 150 steps and your table is setup at 100 the engine stalls, or vice versa and the engine idles at 1500rpm

Just got to be to much so I swapped them all off to pwm and perfection. Use warmup mode and command different idle percent to raise and lower idle manually and it does what it's told, closed loop with idle correction, all my motors run in the 25% range hot idle and so every time. Ive had my 2j car (which came stock stepper motor) running pwm for like 4 years now with zero idle issues. It just works

Edit, I started a thread on the stepper problems and it sounded like the behavior is what people wanted way back when
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Subaru_EA82_4EAT_AWD
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Re: IAC valve options

Post by Subaru_EA82_4EAT_AWD »

nathaninwa wrote:... I swapped them all off to pwm and perfection. Use warmup mode and command different idle percent to raise and lower idle manually and it does what it's told, closed loop with idle correction, all my motors run in the 25% range hot idle and so every time. Ive had my 2j car (which came stock stepper motor) running pwm for like 4 years now with zero idle issues. It just works
Sounds promising, so is it best to match the valve to a similar sized engine as it came off or will any work okay?
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
nathaninwa
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Re: IAC valve options

Post by nathaninwa »

I've ran all kinds on 6 and 8 cylinder motors. Didn't seam to care much Maybe others can chime in

If your junk yard hunting, maybe stick with the v6 and v8 models
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
Subaru_EA82_4EAT_AWD
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Re: IAC valve options

Post by Subaru_EA82_4EAT_AWD »

Thanks.
So even though I'm fitting it to a 1800cc engine?

Do you have any specific setting info, you've found works well?
Want a neat way to Check & Set Ignition timing AND CRANK the motor at the same time BY YOURSELF?
A little thing I made up... https://youtu.be/PajlPNF5mmQ
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