^^ Sounds like the slide stop needs to be opened up a bit.

 

Or you could re-adjust the air bypass screw on the AFM ( Mixture adjustment ). The slide opening and AFM mixture setting have to be matched during warmup. If the CFM flow of one AAR is different from another then the idle mixture adjsutment on the AFM has to be adjusted.

 

 FYI:  FSM says idle mixture on 75 and 76 models cannot be adjusted...but that's not 100% true. Depending on Model of AFM it may have an aluminium plug in it ( " Tamper proof plug ) .. but it can be easily drilled out and  removed. Later models, with Catalytic convertors, had no plug or a rubber plug covering the idle mixture bypass screw.

Edited November 7, 201410 yr by Chickenman

I'm going to give one of these a shot.  My AAR has never been right.   I installed a ball valve last winter (I just let it warm up and close the valve before I hit the road).  When summer came around, I went back to the original AAR and it was OK but, when it started getting cold out this fall, I had to go back to the ball valve.  For $29, I'm going to give one of these a try.  I'll let you know how it goes.

Yes please do as mine did NOT work for me as you see in my post's. I even took it apart and found nothing wrong with. Threw my original back on and it's working fine right now. But would like an alternative one that works next to perfect.

 

Where did you find it for $29?

Found it on ebay (used).  $29 with shipping included.  As of now, it looks like they have four more for this price:

 

http://www.ebay.com/itm/121238863709

Yes please do as mine did NOT work for me as you see in my post's. I even took it apart and found nothing wrong with. Threw my original back on and it's working fine right now. But would like an alternative one that works next to perfect.

 

Where did you find it for $29?

Did you re-adjust the slot opening amount as I suggested? You should be able to loosen the lock nut and adjust the slider stop.

 

Edit: I'll have to get going and put mine on. It's fairly cold out now, so it should be a good test. Been busy sorting out my Audi... which if you've ever owned a German car, means it's a constant battle

Edited November 14, 201410 yr by Chickenman

Yes I did the adjustment. It did idle higher but still rough. It idled right after installing the original one back on. Again, I am more curious about the operation than anything. It is a good alternative if it works. Just not the one I bought for some reason.

There's not a whole to them.  You can jump a battery to the two terminals and watch it close.  I have a stock one that I "re-tuned" to close completely using that method.  Open passage, connect battery, wait, rotate mechanism until closed completely.

. If the CFM flow of one AAR is different from another then the idle mixture adjsutment on the AFM has to be adjusted.

 

 FYI:  FSM says idle mixture on 75 and 76 models cannot be adjusted...but that's not 100% true. Depending on Model of AFM it may have an aluminium plug in it ( " Tamper proof plug ) .. but it can be easily drilled out and  removed. Later models, with Catalytic convertors, had no plug or a rubber plug covering the idle mixture bypass screw.

This is not right, the top part (no offense).  The AAR just lets metered air past the throttle blade to increase idle speed for a short while.  The idle air adjustment screw on the AFM lets air past the AFM vane, leaning out the fuel-air ratio at low RPM.  You might see a small change in idle RPM if you turn the screw, but it's a side effect of changing the fuel-air ratio.  It doesn't let any more air past the AAR or the throttle blade.

 

The AAR is only active for a few minutes then its internal heater should close it completely.  The AFM idle air screw is used to tune the idle mixture to give the right ratio of combustion products for passing emissions tests.

Update:

 

Mine arrived and is installed AND is much better for my car.  When it arrived, I took it apart and found it to be a simple mechanism.  I adjusted it for maximum air flow when cold and bench tested it with a 12V DC source and it closed completely after about 5 minutes.  Installed it in my 1976 280Z and found that it worked much better than the original (which didn't seem to do much at all despite my efforts to adjust it).  Now I get a cold idle of about 1200 RMP which is good for my motor in cold weather.   After about five minutes it settles down to the speed set by the idle set screw.  I am very happy with it.  YMMV.

 

These are simple things:  Its nice that this version can be disassembled for inspection, cleaning, and adjustment.   

 

Dan

Hey Dan, thats good to know. I think I will try to adjust mine again (bench adj.) and re-install it and see what happens.

I don't see how it could NOT work better than the decrepit AARs I have (2 of them -- can't get either one to work right)!  I've placed one on order too.  The AAR is that last annoying little item for getting my engine to 100%.

Still couldn't get the first one to work properly. Went to local pick a part lot and found one on a 300zx and the guy let me have it for $10! Good deal and it was practically brand new. Got it home, installed it and the same as the first one. Would not idle higher than 800rpms. Cold start was working, you can tell. Before I installed it I adjusted it to open fully allowing as much air as possible thru. No luck. Re-installed the stock one and it works like its supposed to. About 1300rpms down to 800 in about 5 minutes. So again, not sure why this particular AAR doesn't work on my 77 280z but Im sticking to the OE one for now. Its better than the alternative in my case. I was just curious to began with on this alternative and was willing to give it a shot and did. 

I did notice that with the OE there is a lot of adjusting that can be done where as the alternative unit has very little adjustment.

FWIW