Need Help with Idle Issue

[RRoller123]

So, with:

1. the throttle cable completely slack,
2. the air adjustment screw turned completely in,
3. and the throttle plate stop screw completely disengaged from the throttle plate,

the engine still idles at about 700-800 on the tach. This seems odd? I would expect that I could get it down to zero, i.e. stall it by starvation. I have searched endlessly for air leaks both visually and with a propane torch at all the possible leak spots. Anyone know what might be going on? I am going to go recheck the timing with my light, maybe that is it and it is just too far advanced? The symptom that prompted all this investigation is a persistent stumble and miss at idle, car runs great otherwise. Plugs are perfect color, no fouling, great consistent compression, 145-150 all cylinders.

[Kevin1]

The air has to be getting in somewhere. Have you checked to see if the auxiliary air valve is closing completely? Plug the hoses between the Aux air valve and the intake (both sides) to determine if that is where the leak is from.

[RRoller123]

Will do that next. Thanks. I did test the AAV awhile ago and it seemed ok, but this is certainly worth trying again. I looked inside the throttle plate body housing and the plate appears visually to be fully closed, so it is not that. It is also very clean, so there is no schmutz holding it open a little.

[RRoller123]

Thanks for the suggestion, I think I found it. For future reference, it appears that there is a tiny split along the bottom of the nipple that protrudes just after the AFM for the AAV line. Created in tightening the stock METAL tube that runs over to the AAV. This was easy to miss and I have looked at it many times. So I ordered a new boot (and silicone lines as well) from AR.