Coldstart valve or Air regulator ?s

[TooSicks]

I've got an '89 fastback, ka24e, and i'm working on reducing as many electronic engine controls as possible to simplify the system and have a couple of questions about the Air Regulator. From what i understand the AR valve contains a bimetallic strip which when heated by an electrical element actuates a valve closed which cuts of the idle air flow. I'm guessing the ecu controls this by using input from the Engine Temp Sensor. I plan on using my Fast Idle Control Valve to allow additional air and controlling it with a dash mounted rocker switch. (i did similar mod on my prelude) I'm removing the AC system so i don't need the FICD for that and i want to remove my AR to clean up my intake and get rid of that mazelike pile of rigid vacuum and cooling tubes.

Can i just remove my AR and use the FICV manually from my rocker switch or will the FICV not flow enough air?

If i used a good filter on the Idle Air Control Valve and separated it from the rest of the intake would it cause enough of a difference to the Mass Airflow Sensor that the missing air would cause a lean condition in closed loop operation?

If it makes a difference I plan on putting a closed loop compensation circuit in that tricks the the ecu into thinking the airflow is there.

I'm trying to remove anything that is not critically essential and clean up my engine bay (something nissan engineers never considered was a simple layout) and make everything in it easily accessible.

So far i'm planning on removing the AC system, the AIV system and the EGR aside from the above mentioned stuff.

Thanks for any help.

[wiwalsh]

If you just chuck some of the equipment without planning your computer will assume its malfunctioning. You might consider getting a reprogrammed ECU from JWT. They will program what you want out of it, so you can remove the crappy emission sensors and valves without consequence. The only drawback is that it costs some $$ (thats what im saving up for myself)

[TooSicks]

For compensation I plan on using resistors to emulate the devices that I remove. The air regulator uses a heating element, which will have a set R value. If I replace it with a resistor with same value, ecu thinks it's there. I don't want to buy a new ECU beause for the future i'm planning on gong with the SDS system with ign. control and building new straight runner velocity stack intake and eq. length turbo manifolds. I won't get the SDS for like 6 months and i can't wait that long to drive my 240, it's been 3 weeks and i already have 240 dt's *L*

[BlackHat]

Digging up the old posts now. Sorry, I wanted to keep the information in a place everyone could search and find it.

My question is about how the Air Regulator functions. I understand the Air Regulator is for open loop idle conditions and that it opens and closes the valve according to temperature. Correct me if I'm wrong, but wouldn't that make the connector attached to it just a sensor of sorts that tells the ECU when the Air Regulator is open or closed?

I'm curious because as I understand it, the AAC and FICD valves are solenoid valves... that would mean they are either 100% open or 100% closed. The only way to regulate the air coming in that way would be to regulate the orifice size right? So the AAC and FICD would stay closed as long as the ECU saw that the Air Regulator was open and as soon as it closed the ECU would switch to closed loop and use the AAC for idling and kick on the FICD whenever the A/C is turned on correct?

If someone could verify all of that as true I would greatly appreciate it (or verify it as wrong and correct me )

[vancouverbc]

There is no sensor by the air regulator. The computer opens and closes air regulator so computer obviously knows when it is open or closed.

The AAC and FICD are controlled by solenoid via on off pulses from computer . The more on pulses the longer the solenoid is open.

If you want to test whether aac is closed when air regulator is open, squeeze the hose going to aac and see if it makes a difference.

The FICD is small compared to AAC. Not sure how big the ar orifice is.

[vancouverbc]

pics at end of this thread.

zerothread?id=124542

[BlackHat]

arrggh... what a nightmare...

I also found an offline resource that says that the FICD valve not only is used when the A/C is turned on, but will also turn on if the AAC valve requires extra air.

Thank you for the help.

[vancouverbc]

I've been curious about whether the FICD is only used for air conditioning.It wouldnt be hard to measure when the FICD is getting power from computer. I think there is some info on the FICD and AAC wiring and how to test the solenoids in the thread i posted.

I think the AAC and Air regulator are useful. Unlike the AIV. Just keep the AAC clean.

[BHayes_S13Coupe]

My air regulator has become loose on my 90 SOHC KA24E and now the car won't hold idle. I thought it was a vacuum leak at 1st. Now that I found the problem, whats the best way to fix this? The top bolt is completely gone and the bottom bolt is loose. Its super cramped in there and hard to get to both bolts. I was going to take the collector (part that contains the throttle body) off and just tighten the A.R. that way because its way to cramped to get any hand tools down there. What's the best way to this? and whats the correct bolt size, threading, etc. to replace the bolt with?

Thanks-Brandon