1980 FIAT 124 Spider

[JoeIllinois]

Hi, Would some one please tell me the VOLTAGE applied to the auxiliary air regulator and at what stage is on and off.
Thanks,
Joe

[rlux4]

It receives 12V, this heats up an element in the body. The aperture closes with heat, the heat comes from the head/coolant temp as it raises and the little heating element in the AAR helps it warm up to close. It's not on and off like your thermo/time switch. If the ambient temperature is above 75-80 it's probably already closed.
Ron

[JoeIllinois]

Thanks Ron, for the info, I now need to check the wires that supply the 12 volts to the AAR because there is zero (0) Voltage on the end of the plug.
I'm now fiat owner, and I'll appreciate any suggestion if there is an easy way these wire can be checked?
Thank you kindly.
Joe

[rlux4]

You need to download Brad Artigue's electrical diagrams. They're about the best available and the nice thing is you can go to Kinkos and have them print any size you want right off the internet. HIs electrical diagrams will give you the info you need. Mine are 11"X17" and very easy to read.
http://www.artigue.com/fiatcontent/wiri ... 0_1982.pdf
Ron

[JoeIllinois]

Thanks Ron very much for your kind help.
I've seen from the schematic that one wire of the valve is connected to the pin number 34 of the ECU.
At what stage does the ECU gives the voltage to the pin 34?
At cold start?
At idle?
When driving?
When accelerating?
Does the voltage remain always active when the engine is on? If not, when does it go off?
By a digital voltmeter I've measured the voltage at the leads of the valve either at cold start and at idle but the voltage was always zero.
Please, reply when possible, I appreciate.

Cheers,
- Joe

[bradartigue]

Thanks Ron very much for your kind help.
I've seen from the schematic that one wire of the valve is connected to the pin number 34 of the ECU.
At what stage does the ECU gives the voltage to the pin 34?
At cold start?
At idle?
When driving?
When accelerating?
Does the voltage remain always active when the engine is on? If not, when does it go off?
By a digital voltmeter I've measured the voltage at the leads of the valve either at cold start and at idle but the voltage was always zero.
Please, reply when possible, I appreciate.

Cheers,
- Joe

It really is not very fancy. AAR should have +12V when the ignition is operating. The AAR is very simple, there is a hole and a metal cover with a resistor on it. When the resistor heats up the metal cover closes the hole. It has no other intelligence and, once your engine compartment is hot, it will close on its own anyway regardless of power because the element got hot (it will just close slower than if powered).

ALL the AAR does is increase idle speed by introducing more air into the plenum. It does not feed back any status or anything else to to ECU and, regardless of its high price tag (remember when these were $25.00 instead of $250.00?), is about as dumb as a stump. If the AAR is malfunctioning and stuck OPEN then it will not affect cold starting but the car will idle too high and be difficult to tune. If it stock CLOSED then it will be a little sluggish when cold, idle low, but as the engine warms up it will regain normal idle.

I actually don't know if the FIAT ECU ever turns the AAR off. Depending on the design it either self-opens when the metal flap closes the door (this is how many BOSCH parts work) or the ECU gets the temperature reading from the forward temp sensor and shuts down the 12V, or it just leaves it consuming +12V.

[azruss]

glad to see you back, Brad

[bradartigue]

glad to see you back, Brad

a little break never hurts me. i had to get away from the quinientos conversations. now that ffo is over there will be less of that nonsense.