Replacing AAR, aka "cold start valve", discouraging options Options

[Prospectfarms]

My AAR shorted-out melting the ignition harness. There is infinite continuity between the pos. terminal and ground. Air passes freely through the valve despite heating the housing to 160 degrees F. (IMG:style_emoticons/default/blink.gif)

My research indicates used OEM valves cost about $90. Typically these don't come with a guarantee. "Rebuilt" or NOS units cost about $200. "Cold start valves" of a similar configuration, e.g., VW, 944, Datsun, Mercedes, etc. begin at $140. Moreover, the off-brands on E-bay are pictured to be identical to the Bosch unit, and that gives me pause. (IMG:style_emoticons/default/huh.gif)

Many members of this forum have friends with stashes of old parts to trade, I don't, and am relying on the market to source replacement parts. My car starts and runs without it andI don't want to spend $100, let alone $200 for this part; however, I recognize that the AAR vastly simplifies tuning and the general operation of the motor. (IMG:style_emoticons/default/idea.gif)

Should I:

1. Attempt disassembly and repair of my AAR, per Anders, et al?
2. Purchase a used OEM valve without a warranty?
3. Try a non-stock unit?
4. Go without AAR (how to tune?)
5. None of the above?

Maybe someone has an AAR for a 1.7 FI motor they would like to sell for less than $90? (IMG:style_emoticons/default/pray.gif) If so, please let me know that too. Or if that's bad forum etiquette,(IMG:style_emoticons/default/chair.gif) just tell me I should place a Wanted ad in the classified forum.

[Dave_Darling]

The AAR is bone-simple. Once you get into it (the "lip" of the housing is crimped around the "lid" that has the pipes coming out of it) you will see how simple it is.

It has a rotary valve, which is a shaft with a hole through it side to side. That is on a bi-metal spring that acts as the thermostat part of the valve. And down in the bottom is a coil of resistance wire that gets hot when current goes through it. That's all there is to it!

You can replace the resistance wire with ~13 ohms of resistor, but make sure you use resistor(s) rated at 1A or better. And check for clearance with the other parts in there. Solder them in; one end of the resistor (or of the chain of resistors if you need to use more than one) should be fastened to the housing, the other should go THROUGH the housing to have the power wire connected to it. Or run the wire (with insulation!!) through the housing to the end of the resistor. Just make sure the power wire doesn't touch the housing, or you'll get a dead short to ground again.

Make sure the shaft of the rotary valve actually rotates in place. Penetrating oil is your friend for that; you can also use a screwdriver in the end of the shaft in the slot that the spring slides into.

If you like, you can glue the top back onto the can with RTV. It's not necessary, but it can be a little easier than folding the lip of the can over the lid.

What's the worst that could happen--you could break the AAR so it doesn't work any more? You're already there! Just be careful that you don't short the hot wire to the cannister, which is the ground for the AAR.

--DD