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?

[SirAndy]

CHT?

Could be. I have seen this exact behavior when the CHT had been disconnected ...


Does it smell rich after warmup? A disconnected CHT will dump lots of fuel into the cylinders when warm.
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[Prospectfarms]

CHT?

Could be. I have seen this exact behavior when the CHT had been disconnected ...


Does it smell rich after warmup? A disconnected CHT will dump lots of fuel into the cylinders when warm.
:idea:

Dear Sir,

I appreciated your post 'cause after reviewing Anders I'd become over excited about the ignition timing. I once worked on a car where the dizzy simply shut down when the engine reached a certain temp, and that took forever to diagnose, but I don't think that is my issue here.

Your comment reminds me that, if the hypothesis is a fuel delivery issue the only conditions relevant to that analysis are "lean" or "rich." Engine stall because of either can offer identical symptoms (besides smell). I need to determine which it is.

I wondered / hoped whether that might be CHT, but I'm working in the breeze so I can't remember whether exhaust smelled rich. I'll repeat and pull a plug right after it stalls.

Another thought was that some failure of primary injectors meant that engine would "lean out" after cold start valve shuts off; however, further reading tells me that CSV shuts down much sooner that the 10-15 minutes of idling I observe prior to the engine stall.

I check the exhaust smell and CHT continuity this AM and report back.

Thanks again!