Air regulator

so this do hickey contraption is another technological piece of wizardry that is supposed to make life (owning a 300zx) easier/better i guess. Its located just behind your throttle cable cover, about the center line of the car. There are only two 10mm bolts holding it in, one in plain sight, the other underneath is a PITA to get to. 2sm hoses and an elec connector and the thing is out.

there it is from the top view with two spade connectors for elec connectors on a bracket also bolted to it.


theres looking from the passenger side inboard. you can see the white elec connector underneath the fat hose.


From what i understand It's job is to regulate some air flow to help with cold starts, specifically with your idle. thats just my cliff notes version you can go way into detail here- http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=920448&forum=technical&dtSearch=0

Anyway, the reason for my whole encounter with this unit is due to a hissssssssssing sound from it when i go to attempt a boost leak check. under only 1.5psi it's hissing away.

It took a while to find it but some soapy water and a mirror let me see the leak on the underside of the AR.



when i first found this to be a leak i tried some JBweld thinking the housing was cracked. i applied the JB goop while it was still installed with a stick.


not pretty i know, and soon after, the problem was back. i either didnt cover it good, or the JB cracked. It seemed brittle when i was just chipping it away (more on that later..)


so finally i did the right thing and researched instead of trying to troubleshoot on my own.. saw how -relatively- simple it was to take out, and so i yanked it.

i meant to snap some pix of the JB and orange mess before i chipped it off.. but oh well.. its all off now.. and what i realized was there was an adjustment screw under it with 2 washers. under that was a huge gaping hole.
-this cant be right-
i dont understand how just those two washers are supposed to create an air tight seal there. it IS supposed to be airtight right? its like im missing an Oring or gasket or something.

so i have it out.. may as well see whats inside.


4 screws and the nut that was covered with goo.. wait.. what is that???


no, not all the black grime in the circle part..



THE HELL??

so maybe that was blocking operation hence my funny idle. or maybe it was all the gunk built up.

halfway done cleaning. what a big difference.


so as of now, it's still in pieces while i wonder if im missing some gasket/seal.

for now until i get some help from you all, im going to run some electrical tests on it as outlined by the earlier TTnet link.

resistance is good at @ .74 ohms... buttt running 12v directly to it im not getting the opening i think i should. it clicked a few times but didnt do much in about 2 min. maybe i didnt let it heat up long enough :shrug:

well, its reasembled now.. but im still sketchy on the screw with the orange goo. saw another pic someone else had the same crap on it.

so tomm at work, (i already teflon taped the threads) im going to throw some RTV on top of it to see what happens.

Great job on the overhaul of the Air Regulator. The orange stuff you are talking about is an external thread locker to lock the adjustment screw in position once it is set. The last time I set one it took about 5 min for the valve to close. The adjustmet screw is to make sure the port is closed once heated thus reducing the idle speed.

Clay

soooooooo if its cold...
not installed even, and the port is closed.. then i have a bad valve yes?

It is probally just out of adjustment. when it is cold you should be able to see through the opening and this will allow your engine to have a high idle for cold starts. As the element warms up the port will close and the IAAC will control the idle. Here is a link to TT.net that explains it very detailed and how to adjust the Air Regulator.

Clay

http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=920448&forum=technical&dtSearch=2

TTvert wrote:

The orange stuff you are talking about is an external thread locker to lock the adjustment screw in position once it is set.

Told ya, Nate!

i did reda the writeup on TT before i removed it and saw it was supposed to be open a tad when closed. My elec connection was super corroded, myabe thats why it shut in a closed position. dunno. but the lil 'pen' spring was fine. maybe the bigger one wasnt doing its job right to open it.

not that i didnt believe you steve, but i was questioning if that was from the factory or a hackjob someone else did. and also.. why is there no real seal there? because mine is def leaking air on boost leak check.

tomm or the next, ill be reinstalling it. it's coated with some clear RTV now.

I expect it's hard to get a seal around threads w/o using sealant if you can't drive the head fully down on the top surface. I need to take a look at mine once I get the cover off this weekend after the thaw. Mine's never been touched so I can see what 'factory' looks like.

The fault, IMO, is that the sealant is brittle after setting, and after long-term vibration and temp cycles, it cracks.

the screw is real tight.. but the lock washer has a gap and that sits on the regular washer.. both in the last pic. all that metal to metal contact.. no way its air tight.

I have 2 0r 3 laying around, I will ceck them to see if mine are sealed or not.

Clay

2 or 3?? dang. yeah, please let me know! also, if they all have the orange stuff on the adjust screw.

I checked the ones i have and they all have the orange stuff on the adjustment screw. I have not had a chance to check the operation again ( I was tearing down Evans engine thiis weekend) I will get to them tomorrow and let you know tomorrow evening.

Clay

I checked the 2 that I have and as I said before both have the orange stuff sealing the nut and threads. One of these came off of an engine that was severly overheated and the orange stuff was loose and would have been leaking. I checked the operation and they both have just a sliver of a gap when cold. As the element warms up the port will close. if your valve is fully closed you will nt have the hight idle when cold. I hope this helps

Clay

right on point!
high idle when closed.
after warming it settles down.
i just installed it tonight and will report back when i get the leak tester on.

Regulator doesnt seem to leak anymore. well, not to where i can hear it. i also sprayed it with soap/water and no bubbles. yet i still cant build past 1.5psi WTF.

now, idle is constantly high, warm engine or not. dunno if its due to a stuck -closed- regulator.. or because i cleaned all the corrosion off the contacts and idle now needs readjusted. Volt test on the AR i thin kwill be first business along with monitoring AAC/TPS.

Did you ever get you Idle to slow down?

Clay