Help me understand the AAR please.

[siteunseen]

I'm pretty sure mine is toasted. I'm going to a junkyard that has 3 old Z's and want to know if I know how to check if they're good. Does the whole thing turn, electrical connector and all? Or does the connector stay and the 1/2" x 2" long metal strip with the wires wrapped around it turn by itself? I put the metal strip in a vise and it won't budge. Put 12 volts to it for at least 5 minutes and still no movement. The only way I see it could turn is where the connection slides in the housing. So if I find one that the electrical connection turns slightly to the right while in the housing would that mean it's probably good? Sorry for any confusion, I'm not too good at 'splainin things.

Thanks for any replies. Cliff

[240260280z]

http://atlanticz.ca/zclub/techtips/aar/index.html

[siteunseen]

So it doesn't turn at all, it bends to the right or left. Thanks Blue!

Bi-metal slowly rotates to a position that can no longer operate shutter

AAR gets gunked up by oily engine fumes that are re-circulated.

Electrical connections to AAR corrode and stop conducting.

AAR suffers mechanical failure due to bi-metal lever rotation.

Edited October 1, 2012 by siteunseen

[TomoHawk]

Isn't there a way to substitute a solenoid-operated valve or similar that won't fail after a few years?

[siteunseen]

Wow, what a difference that made. I found one on a ZX that looked good (the hood had been kept closed) and when I was cleaning it up I noticed the connection plug was at an angle where mine was level. Also there is a rolled pin in the ZX AAR that keeps the metal strip and the connection from turning like mine had done.

[Zed Head]

Mine came apart like yours did when I tried to take the connector off. If you got a good one from a ZX, it should swap right in. You could have "calibrated" your broken one by clocking the piece that came out, and testing with a battery and some jumper wires until it opened and closed correctly, then using epoxy or similar to lock it in place, but it's simpler to just get a used one and clean it up.

They're not really supposed to come apart.

[Captain Obvious]

Mine was giving me trouble, so I carefully opened it up to clean it out and adjust. Then I drilled and tapped the casing for three small screws to hold the clamshell back together. Now I can disassemble and reassemble at will. Not supposed to come apart? Mine is! :laugh:

Sorry for the crappy pics, but I didn't take it off the car just for a photo shoot.

Two screws on top:

And one on the bottom:

[Wade Nelson]

http://www.classiczcars.com/forums/thread46090.html

[TomoHawk]

IIRC, there is supposed to be a block under the AAV with coolant going through it, so it should be experiencing the actual engine temperature, instead of the temperature of the intake manifold, which is shielded from the exhaust manifold to stay 'cool.'

I"m surprised that it doesn't fail about a year after it's installed, as the element inside stays (hot) all the time that the engine is on. There ought to be a kind of manual electric valve that you can control from the driver's seat. I keep thinking of the choke units on carburetors... How do those work?

[Captain Obvious]

Right you are, and good to bring that up so other people don't think that my car is "normal". What's missing on mine is the "thermal vacuum valve", and in addition to providing a "hot plate" for the AAR, it also enables/disables the EGR system based on water temperature. Mine was removed by a previous owner. I'm probably going to put mine back on, but it's lower priority at this point.

I was worried that without the heat from the TVV that my AAR would never get hot enough to completely close, but that hasn't been the case. I've got my AAR adjusted to only provide a very small amount of additional air when cold, and it seems to generate enough heat with the internal heating coil to close even with the missing heat from the TVV. Of course, I haven't driven the car in any really cold months though. I might miss that TVV heat more in Feb than Oct.

As for the issue of being always on, I (like you) am a little surprised that the AAR heating coils don't burn out more frequently. I believe the reason they don't burn often is that while the current is always present, it's pretty small. My AAR coil is around 60 Ohms, so at 13.6 V it draws less than 250 milliamps.

And one more... I (also like you) thought about the possibility of ditching the AAR and using a solenoid valve(s) to control the auxiliary cold air around the throttle plate instead. My first stumbling block with this is that the solenoid valves are ON-OFF as opposed to the gradual "analog" closing of the AAR. I guess you could use a couple of solenoid valves in parallel and close them at different temperatures to simulate analog control, but that's more switches and more complexity. Not sure if it's worth it.

[TomoHawk]

I remembered the warming plate because I found it in my tub of "unneeded spares" after the engine was installed!

Unfortunately, the L28 engines don't have the coolant "temperature switch" that the earlier engines had, but I think you could install one in the same location. That way you'd at least have a way to activate some kind of valve at the right engine temperature (when it's "warm") and not really needing to watch the temperature gauge, or run more wires inside and install a switch.

If you couldn't install the OEM coolant switch, I think you can get a temperature switch that you could probably bolt on to the thermostat box.

[siteunseen]

I too removed the EGR and Thermal Vacuum Switch when I put on the header. The MSA header I bought won't work with an EGR valve, don't know about others. Until I found the broken AAR I thought removing the TVS was my "hard to warm up" problem but it wasn't thank goodness. This guy says he sales a manual valve but I didn't find it so maybe you have to email him.

If you have cleaned it, adjusted it and still can't get it to open and close properly you will have to buy another. They cost about $70 for a GTV6 and as much as $130 for some other cars.@ If you want you can buy a manual valve from me. It's a permanent fix and will never need to be replaced or cleaned. It also provides even better cold starting and slightly more power then a perfectly functioning Bosch AAV. It's operated by a manual cable, pull it out for starting and push it in after a few minutes of running. The manual AAVs are for sale at the bottom of this page.

http://www.hiperformancestore.com/Ljetronic.htm

Edited October 3, 2012 by siteunseen
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