How does the air regulator works ?

[bigboss59400]

Can someone explain how does the air regulator works ?

I don't see the point of it being connected to the fuel pump ?

I also don't understand how it can regulate air ? if so based on what ? temperature ?

[GTSBoy]

It's not connected to the fuel pump. It's connected to the same 12V supply as the fuel pump, so that it is only heated when the fuel pump is active (ie, mostly when the engine is running).

In case that wasn't clear, it is heated. Electrically. When it is cold, it is open and flows air. When it is warmed up, it closes, and does not flow air. Hence, it is a cold engine idle up.

[wardiz]

Depending on the coolant temperature and on the target engine RPM it closes and opens quickly to achieve the required target. It's a kind of duty cycle.

[joshuaho96]

55 minutes ago, wardiz said:

Depending on the coolant temperature and on the target engine RPM it closes and opens quickly to achieve the required target. It's a kind of duty cycle.

Intake air regulator is not the same as AAC valve. Intake air regulator is only there to raise the idle airflow at cold start. After a certain amount of engine runtime the shutter should fully close and all idle airflow goes through the AAC valve instead.

[wardiz]

I didn't know that about the air regulator thank for the info.
According to the pinout it looks like it's not controled by the ECU, is it ?

[GTSBoy]

It kinda is controlled by the ECU - in that the power to run all this is from the ignition relay which is all tied up in a loop with the ECU and the ECCS relay.

[Dose Pipe Sutututu]

Unpopular opinion, rip all that junk out (AAC, IACV, TB, Cable throttle, etc.) throw it all into the recycling bin.

Go DBW throttle. 

Superb idle control, throttle response, cruise control, and all the fun stuff like throttle blips, rev matching etc.

[joshuaho96]

8 hours ago, wardiz said:

I didn't know that about the air regulator thank for the info.
According to the pinout it looks like it's not controled by the ECU, is it ?

As others have said it is technically controlled in the sense that the ECU turns on the fuel pump which also turns this thing on. Other than that there is no real control. So you could in theory do something stupid like repeatedly prime the pump without starting the engine and that would cause the shutter to close and the cold start idle to be too low. I believe the NEO series might have a thermostat controlled cold start valve instead but I've never been able to disassemble the idle valve.

3 hours ago, Dose Pipe Sutututu said:

Unpopular opinion, rip all that junk out (AAC, IACV, TB, Cable throttle, etc.) throw it all into the recycling bin.

Go DBW throttle. 

Superb idle control, throttle response, cruise control, and all the fun stuff like throttle blips, rev matching etc.

Not wrong, but the actual physical intake air regulator + idle valve isn't the issue for packaging in an RB26 so much as the giant common vacuum chamber hanging out under the intake plenum which is still needed for the brake booster + BOV vacuum lines if you're keeping it mostly stock. I've kind of made my peace with it.

[GTSBoy]

4 hours ago, joshuaho96 said:

I believe the NEO series might have a thermostat controlled cold start valve instead but I've never been able to disassemble the idle valve.

Neo has a combined IACV and AAC on the back end of the plenum. Coolant heated (it's got a bleed point on it). No electrical heat. Works very nicely when it is clean.

[wardiz]

Found this in the engine workshop manual about the air regulator.