Air regulator Q and a WTB

[teddy]

Does the air regulator open up manually based on temperature, or rely on the sensor to open and close it? My car is always stalling/idling very rough so I examined the regulator. I used a hose to try and blow air through it into the intake manifold and could not. I tried blowing the other way and that was pretty difficult too. So is this valve supposed to be open with the engine off, or does it open up when the engine is on?

Also, I'm in need of a coilpack harness. Just the section with the ground and the 4 plugs to the coil packs. Mine are very very cracked and broken and are being held on by zipties.

[dattodude]

Cold idle is bumped up with the regulator under the throttle body. It slowly closes over a period of 10 minutes. It is not adjustable and closes using a bimetal strip that has 12v from the injector power supply connected to it.

Base Idle is set by the fixed adjustor on the block on the side of the plenum. IT can only be set while the AAC valve is disconnected.

Airconditioner Idle increase is set by allowing a fixed amount of air past the TB, using the blue connector (FICD) on the idle block on the plenum. Without A/C connecting this is pointless.

The AAC valve is a pulse width modulated valve, that opens and closes to raise the idle when the engine is about to stall, or if the base idle is set too low.

The problem with CA18s is that this idle control block gets chocked with carbon rubbish, so the base idle drops as a result of this restriction, and everything else starts going 'poltergeist' after that.

The AAC valve has to work 'all of the time' to keep the engine from stalling because the base idle (mechanical adjustment) isn't providing enough air bypass to maintain an idle of 850rpm.

People talk about CA18s with a bad idle, where it jumps up and down. This the AAC valve trying to do the job of the base idle adjuster.

The engine also can set idle higher through the AAC for when it is cold. If the engine temperature sensor is faulty, this can also result in strange idle problems.

So there..

- Clean the AAC/FICD valve block as a first measure. Be careful not to break the gaskets when you remove it to clean it.- Clean or replace the Cold idle solenoid. They can get choked up with oil/carbin rubbish too. Although it is less common.- After that, when the engine is warm, while the engine is running, remove the AAC valve connector. And set the 'base idle' to 850rpm using the 10mm bolt/screw on the rear side of the idle control block. Reconnect the AAC connector. This is your idle set using the proper method.

Cheers,Chris

[UMS_CA18DET]

The Air Regulator is used for Cold Starts as the motor warms up it lets less air in until it gets to around 160* F then it closes and the IACV takes over, the IACV takes care of idle after the car is warmed up.

[teddy]

Thanks for all of the info and quick reply. All I'm really trying to figure out is if the regulator is bad or not. I've cleaned the iacv and the cold idle solenoid twice to no avail. I can't set the idle regardless since the engine doesn't stay running for more than 5 seconds unless the throttle is held open or the maf is unplugged.

So assuming my regulator was stuck shut, this would cause the car to fall on it's face due to the lack of air present?

[dattodude]

the hole should be 5-8mm when cold. If you have to blow hard through it..it's stuck or clogged with crap.

I've pulled these things apart before, only 4 setscrews. Pull it apart and flush it with some carby cleaner or metho. It should allow at least the airflow a straw from mcdonalds would give.

A broken one will not close up. A clogged one will not reopen.

Cheers,Chris

[teddy]

Gracias senor. I pulled the regulator off just a few minutes ago and flushed it with some carb cleaner. It didn't just flow out the other end like a river, but it came out. Probably similar to a straw. I then tried blowing through it and now I can get air through it, but it's still kinda difficult. Also what was odd was I tried to put some degreaser through it to see if it'd loosen up some gunk and dirt. But it didn't drain out like the carb cleaner. It just sat in there and I had to blow through it to get it to come out.

[Bwana]

I think I might have the harness you're looking for... I know I have a complete set of coilpacks. I need to make a thread and just get rid of some of this stuff. I'll check on that harness for ya.

[teddy]

I think I might have the harness you're looking for... I know I have a complete set of coilpacks. I need to make a thread and just get rid of some of this stuff. I'll check on that harness for ya.

sweeeeeeet. Let me know.

[Bwana]

I'll run out and check on it real quick for ya

[Bwana]

Yep, I've got it, and it's as perfect as a 50k harness gets. Email me, bawana @ frii.com and I'll get ya hooked up.

[rico05]

I decided to go ahead and just get a new air regulator. The Sentra one plugs right in.

http://www.thepartsbin.com/rep....html

Didn't help me at all, lol. But I now think my issue is fuel anyway...