Low idle when cold (Fi car)

[Tobi]

I just replaced the auxiliary air valve on my 81 Fi car with a used one that I bought on e-bay and I still have a low idle.
What is a good way to test it and could there be a different reason for a low idle?
It starts well just does not want to stay on for the first 2 or 3 minutes.

[2ndwind]

Is this a sudden problem, a gradually occurring problem or did you buy the car this way?
On fuel injected cars, the temperature sensor at the coolant tee, at the front of the engine and its connection are critical to the ECU controlling the idle. Also, there is an idle screw on the throttle plate. The rubber seal in mine was cracked allowing too much air in, causing HIGH idle. But if someone screwed it all the way in, I suspect that would result in poor idle. Download Brad Artigue's Fuel Injection manual here: http://www.mirafiori.com/faq/fiatFI_may2002.pdf

[bradartigue]

Download the more better version, that 2002 one is buggy:

http://www.artigue.com/fiat

The direct link to the file:

http://www.artigue.com/fiatcontent/Arti ... 124_MM.pdf

So...........that AAR is really a simple device; so simple it will make you angry if you ever buy a new one at full price. All it is is a metal strip and a resistor. The resistor is a heater. When you give it power it heats up and closes the strip. Nothing more to it.

Test the AAR: Remove it and stick it in the refrigerator for a while. You should be able to blow throw it. Now heat up an oven to 125 degrees (it doesn't need to be any warmer) and stick it in there for a while. Figure out a way to blow through it now (don't use your lips). It should no longer allow air to go through it. If this fails then take the AAR and fill it with carburetor cleaner, shake it up a lot, then drain it, fill it with WD-40, shake it up a lot, then drain it, fill it with carburetor cleaner, and drain it. Plug it back it. It may work. That strip can stop moving with any resistance like oxidation, and it's likely your AAR is 20 years or more in age.

All that said if the car runs fine when warm and the AAR is kapuut then find another...they don't fail often.

[Tobi]

Thank you guy's, I had the artique file downloaded a while ago and forgot about it.
It has been working a bit better the last days so it is probably corroded. Who knows how long that was out of use before I got it.
I will try the fridge and heat test and I am not going to use my lips for the hot test
I got electronic cleaner, does it have to be carburetor cleaner?

[bradartigue]

Actually electronic cleaner is better if you have it (evaporates faster); it's just more expensive, $5 vs $1 or so.