Cant Find Air Regulator Plug...

[Gameboy]

Ive been doing an rb25 into s13 conversion on and off for a while now. Im putting the harness in but I cant seem to find the air regulator plug. I know of the AAC plug (the purple one) but cant find the other one. Is it part of a separate harness?

[89CAL]

No they should come out together. Look for cut wires. If the harness is wrapped in electrical tape then the plug may have been cut at the harness and then wrapped up. Not sure why though

[GTSBoy]

Not sure why though

The air reg is something that people get irrationally pissed off at. Anything that they don't understand is equivalent to witchcraft.

[89CAL]

Yeah well, that's all I would assume. I forget some people aren't like me and if something doesn't work I'd rather fix/replace it then get rid of it lol

Edited August 21, 2014 by 89CAL

[Gameboy]

OK, so can I hard wire it in instead? I had a look at the ECU pinout and it doesnt mention it. I have another harness lying around and I think it has it but the plug has been torn off...

[GTSBoy]

I think it does just run the whole time the ignition is on.

[Gameboy]

OK sweet, I thought it was something like that. If thats all it is ill just run 12v to it from ign.

[GTSBoy]

OK sweet, I thought it was something like that. If thats all it is ill just run 12v to it from a fused supply.

FYP.

[89CAL]

I think it will be PWM controlled by the ECU. The other plug that you dont have (which is brown in the photo I have, on the valve itself) goes to a solenoid so will need PWM to allow varying amounts of air through

[Gameboy]

Now there's a solenoid? lol damn

I cant take pics as the car is at my brothers work shop but googling around, the plug im missing is blue. The plug that goes into the AAC is purple (have that plugged in) and there is a brown plug I have nfi where it goes. Im guessing that's for the solenoid?

Stupid car....

My sister has a Series 2 R33 and is bone stock. I think im going to have a look at it and see what im missing. I think I have that solenoid in my parts bin somewhere...

Edited August 21, 2014 by Gameboy

[jiffo]

The air reg is simply a 12V bi-metallic strip valve, nothing flash.

No ecu input, just power on when the IGN is on.

Doesn't even need 12V, engine bay heat will eventually shut the valve.

A pain to access on a 25, impossible on a 26.

I hate them.

Not to be confused with the purple plug idle bump up for the aircon.

Or the brown plug for the AAC.

Of course this is presuming the OP is talking about an R33 Rb25 and not a Neo.

[GTSBoy]

Correct.

[Gameboy]

The air reg is simply a 12V bi-metallic strip valve, nothing flash.

No ecu input, just power on when the IGN is on.

Doesn't even need 12V, engine bay heat will eventually shut the valve.

A pain to access on a 25, impossible on a 26.

I hate them.

Not to be confused with the purple plug idle bump up for the aircon.

Or the brown plug for the AAC.

Of course this is presuming the OP is talking about an R33 Rb25 and not a Neo.

Thanks for the post. Its a great help and yeah, its an r33 25.

Thanks guys, love this forum.

[discopotato03]

Just as an added extra people used to power these cold start air valves off the fuel pump circuit say with a relay . The idea being that if the ignition was on for any length of time without the engine running the valve wouldn't be heating and closing up .

As mentioned most engines had these valves mounted somewhere where they got coolant heat early in the warm up phase so that if the power feed failed they'd still heat up and close .

How does the Neo system work .

A .

[GTSBoy]

Neo uses coolant. Same device as the AAC on rear of plenum. Quite different to earlier RBs.

[jiffo]

Although the air reg is IGN "ON" for power, it's actually all part of the fuel pump relay power feed which is controlled by the ecu.

So once the ecu times out the fuel pump, power to the air reg is also cut.

Attached is Rb26 system, 20 and 25 are similarly controlled.

[89CAL]

This is mine and sounds like the plug that is missing is for the solenoid which will be PWM so needs the right ECU feed. This is it

[89CAL]

I'm sure the link g4 outputs PWM to the solenoid to open or close it so much depending on how much air is required, so will have to check that out tonight.

[jiffo]

Yes Cal, the brown plug (AAC) is ecu controlled, varying duty cycle signal.

Your purple plug is the idle bump up for air con, just an on/off solenoid not hard wire linked to the engine ecu.

Of course your aircon control unit (amplifier) does tell the engine ecu to control the compressor's magnetic clutch.

Found a photo of the Rb26 air reg, buried under the plenum.

They all look the same, 20, 25, 26, 30......horrible things.

[GTSBoy]

CAL's pictured unit is NOT THE AIR REGULATOR.