Can somebody ID this new idle quirk?, starts & runs well -- until warm Options

[Prospectfarms]

(IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/beer3.gif)

O.K., I'm better now... D-jet is driving me to drink.

The 1.7 starts and runs well until it warms up. After 10 min. idling smoothly @ 900 it hesitates two or three times and stops idling at all, which means I can't keep it running long enough to set the timing. I can keep it going by feathering the throttle, but my nice smooth idle is gone. I reproduced the symptom three times in a row today.

By clamping off the Vac hoses one-by-one it appears the FI components seem to be doing what they're supposed to. No other vacuum or capacitance probs. found so far. Haven't checked the injectors.

This started after I repaired the ground strap on my distributor -- must have bumped something else. CHT?

I have the FI diagnostic checklists and am working on them. If this was a carburetor I'd say it was running with a clogged idle jet (IMG:style_emoticons/default/wacko.gif) . These symptoms seem specific and uncommon. At least I've not seen others posts that describe the same thing. Did I miss one?

[TheCabinetmaker]

The cold start valve does not come on till the air temp hits about 40F.

The Auxiliary air regulator however, will open up on a 60 degree morning to give extra rpms during warm up. after about 10 minutes it should close and the idle come back to 900 (or wherever its is set). You may just have the idle set to low, or the throttle position switch may need to be reset. A mis adjusted tps will render the idle mixture knob on the ecu useless.

[Prospectfarms]

The cold start valve does not come on till the air temp hits about 40F.

The Auxiliary air regulator however, will open up on a 60 degree morning to give extra rpms during warm up. after about 10 minutes it should close and the idle come back to 900 (or wherever its is set). You may just have the idle set to low, or the throttle position switch may need to be reset. A mis adjusted tps will render the idle mixture knob on the ecu useless.

Great info! thanks. Assumed incorrectly that without extra fuel delivery, an open AAR would over lean the idle mixture -- ECU must adjust for proper mixture some other way.

My cold engine idle is first 800, then rises to 900 in a discrete stage. The third stage is stall. Are you suggesting thesel RPM values may be too low? I.e., if the TBP is mispositioned and the idle set too low, discontinuation of the AAR function would bring it down to a stall condition.

I'm going to check Throttle position sensor and re-check AAR and report.