AAV Opening Size?

[DogRocker]

How open should the Aux Air Valve be? Pic below is mine after spraying with liberal amounts of carb cleaner, allowing it to dry overnight and then putting it in the freezer for about thirty minutes. I applied 12 Volts & it closes.

[RRoller123]

That opening looks ok. I have experimented with 3 of them , which is not a huge sample size, but that one looks about average.

Does it fully close with the voltage applied, so no light is showing through?

[DogRocker]

"Does it fully close with the voltage applied, so no light is showing through?"

Yes.

Before I sprayed it with carb cleaner I tested it on the car by removing one of the two hoses and trying to lightly poke a very thin screwdriver through any part of the circular opening. It was completely closed on a cold engine. The pic above is after some time in the freezer. It just seems logical to me that it should open at least that much or more when cold and even further or completely open when frozen. That's just a guess, since I'm new to these cars.

I've been having inconsistent idling (sometimes seemingly ok, sometimes obviously too low) during warm up. I've checked the Throttle Position Sensor & it seems like the switches are working.

[RRoller123]

Check your CSI (cold start injector) for proper firing when the engine is cold, and that it shuts off after a few seconds, this also indicates the proper action of the TTS (thermal time switch) which controls how long the CSI fires. The leads to the TTS, which is located under the center of the intake manifold, are nearly impossible to see, and you kind of have to feel around for them under there to be sure they are properly connected.

Look very carefully for air leaks through the entire FI system.

Good resources! (I think that the bottom one might be the best)

FUEL INJECTION DEBUGGING
http://www.hiperformancestore.com/Ljetronic.htm

FUEL INJECTION MANUAL
http://www.mirafiori.com/faq/fiatFI_may2002.pdf

L-JETRONIC
http://mastertechmag.com/pdf/1988/11nov ... ronic2.pdf

http://jenniskens.livedsl.nl/Technical/ ... tronic.pdf

L-JETRONIC FI MANUAL (FROM VW)
https://www.type4.org/manuals/ljet/index.html

[DogRocker]

I previously found the first three links, but I haven't seen the bottom two yet. I'll read them over.

I've already checked for air leaks and didn't find anything obvious. I'll be putting on new plug wires, cap & rotor this week and will check the Thermo Time Switch and Cold Start Injector while I'm under the hood.

Thanks for the tips & links!

[RRoller123]

Also that connection at the temp sensor in the coolant T is a constant suspect. You may want to check that beastie out as well!

[DogRocker]

This may be unrelated or not, but I was measuring the AFM and found some high readings...

At the AFM connector:

Pins 6 - 7: 2054 Ohms
Pins 6 - 8: 374 Ohms
Pins 6 - 9: 564 Ohms
Pins 7 - 8: 2190 Ohms

These measurements suggest to me that there's an issue with the wiper arm connection to resistive trace.