So my '81 FI spider started fine but the RPMs were lower than they should be when the engine was cold (almost stalled) but runs fine when warm (30+ seconds). From advice on a post here I removed the AAR, connector the in and out lines and it idled perfect (1800 RPM or so). So I'm thinking...
- the AAR is stuck closed
- the AAR isn't getting the electrical signal to open

I lubed the AAR from the holes as best I could. Can these thing by dismantled and rebuild? I only see 1 bolt on the unit. Also should I be able to put a voltmeter on the electrical connector when the engine is cold and see if it's getting a signal?

hey Richard, not alot of experience with this however, those rpms seem way to high mine starts and idles at 850 - 900 rpm there is an idle adjustment screw fyi

Yep. I screwed the idle screw all the way in. According to tach the rpm is about 1100 but maybe it's not accurate.

I don't believe that it goes all the way in

This is from Brad Artigue manual http://www.artigue.com/fiat/

Run the engine to normal operating temperature. On cars with automatic transmissions,
set the parking brake, block the wheels, and put the transmission in "D". Completely
seat the idle speed screw. Loosen the accelerator linkage stop screw retaining nut and
adjust the stop screw to achieve 800 to 900 RPM on manual transmissions and 700 to
800 RPM on automatic transmissions.

Lock the accelerator stop screw with the retaining nut. Use the idle speed screw (1) to
set idle at 850 to 900 RPM on manual transmissions and 700 to 800 RPM on automatic
transmissions. If idle speed cannot be reached using this procedure, fully remove the
idle speed screw (2) and clean the orifice and the screw itself using a high pressure
spray cleaner (carburetor cleaner is fine)

hope you are able to sort it out

4uall wrote:I don't believe that it goes all the way in

This is from Brad Artigue manual http://www.artigue.com/fiat/

Run the engine to normal operating temperature. On cars with automatic transmissions,
set the parking brake, block the wheels, and put the transmission in "D". Completely
seat the idle speed screw. Loosen the accelerator linkage stop screw retaining nut and
adjust the stop screw to achieve 800 to 900 RPM on manual transmissions and 700 to
800 RPM on automatic transmissions.

Lock the accelerator stop screw with the retaining nut. Use the idle speed screw (1) to
set idle at 850 to 900 RPM on manual transmissions and 700 to 800 RPM on automatic
transmissions. If idle speed cannot be reached using this procedure, fully remove the
idle speed screw (2) and clean the orifice and the screw itself using a high pressure
spray cleaner (carburetor cleaner is fine)

hope you are able to sort it out

Jay,
Thanks. I'll try this tonight.

Richard

Hope you are able to get her running for the upcoming Easter long weekend

I was able to adjust the idle. Turns out the pedal was a bit stuck. When I turned in the screw and loosened the cable stop it still was at about 1100 rpm. I went into the car and lifted the pedal a bit and the RPM went down to about 500 rpm (but didn't stall!). I then lubricated the cable and pivot points (everything moves good) and was able to adjust the idle to about 850 rpm. Seems fairly good but when I press the gas again it stays at about 1000 rpm unless I lift the pedal a bit.

I'm thinking that the 2 return springs on the intake manifold have lost some of their springiness and don't return the throttle back to hitting the bolt stop point... until I lift the gas pedal. I was thinking maybe I could put an extra rotation on each spring to increase the springiness. Has anyone done this before?

The cable stop should have nothing to do with it. cable should be loose at idle.

majicwrench wrote:The cable stop should have nothing to do with it. cable should be loose at idle.

Yep. Just didn't want to make it so loose so it has a chance of coming out. I'll work on the adjustment a bit. It's close for sure.

IF you "lift the gas pedal" and idle slows, cable is too tight!

This is finally resolved. All along I thought it was the AAR and it wasn't. Read this guide more closely....

http://www.hiperformancestore.com/ljetronic.htm

Specifically the section on the throttle position switch.



It mentions you should hear a faint click when you open the throttle from idle. I didn't hear this. I loosened the screws to adjust it and then I was able to hear the click. Here's a video (hopefully you can hear the click).

https://youtu.be/V6xclfY83yg

TIghtened the screws and reconnected the cable. Startup was perfect and idle stayed where it should.

https://youtu.be/0cybXBcG9FA

Hopefully this helps others with the same issue.