Aux. air regulator woes., Engine unit dead, replacement too! Options

[Air_Cooled_Nut]

The AAR is stuck open on my 2.0L. In fact, when I connect it to the power source it pops the fuel pump fuse (25A) (IMG:http://www.914world.com/bbs2/html/emoticons/mad.gif) I put a clamp on the hose so now I have to feather the throttle at stops until the engine is warmed up. Obviously, if I take the clamp off then the engine will idle really fast once op temp is reached.

I found a "spare" unit but it, too, is stuck open. Why can't they stick closed? (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) So, what is there to replace it? I tried the 914 on-line part stores no no avail. AA was a PITA to "flip" thru their on-line catalog (yeah...whatever) and I get bored and gave up looking thru it. The device looks exactly like the unit I had on my previous Type 3 automatic -- which served the same function and was powered by the coil. So I got to thinking, the other units out there, for cars like water-cooled VW engines, use a similar device, just a little more aerodynamic looking (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) Would one of those (less expensive) units work? Can someone point me to a place that does sell AAR's for our cars (not a "I think such-n-such sells them")? What have others done to fix or replace their failing units?

Thanks (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif)

[Dave_Darling]

Auxiliary Air Regulator. It lets air bypass the (closed) throttle plate when the engine is cold. That raises the cold idle RPMs somewhat, and more importantly keeps the cold idle RPMs from being "zero".

ACN, it sounds like the heating element in your AAR has shorted to the cannister. Check the resistance from the plug to the housing of the AAR; it should be about 13 ohms. Bet you find more like zero. If that is the case, opening it up is the only way to fix it--you can pull out the coiled "resistance wire" that's in there, and replace it with about 13 ohms worth of 1-watt (or 1.5 watt, if they make those) resistors. They should heat up at pretty close to the same rate as the original wire did.

You could also adapt a later car's "cold idle air bypass" mechanism to the 914, if you were so inclined. If the bypass is a simple heated valve like the stock part, then you just have some hoses and wires to hook up. Of course, it may let the wrong amount of air through at various times during the warmup, but that'll just mean the engine will idle a "little funny" for those first few minutes of driving, which is probably no big deal.

There's a new 914 owner over on the Yahoo group who replaced the AAR with a manual version (he will be installing a "choke cable" for it Real Soon Now) without even bothering to test his AAR.

But I'd still try to fix the original part if you can.

--DD