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Old 03-20-2019, 06:16 PM   #1
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Runs Perfect, Except Dies On DownRev To Idle.

I have read through a lot of threads about egr, iacv, vac/ exh leak, etc., but my problem isn't 'exactly' the same as others.

My car seems to idle perfect, anytime it is idling, and LTFT and STFT stay at 0 at idle.

My issue is that the engine dies everytime I let it drop to idle on its own.

I can keep it from dieing if I stay in gear all the way down to idle speed before I push the clutch.

Everytime it dies while I'm still rolling, I can let go of the clutch while still in 5th or 4th and it gently restarts and idles seemingly perfect as I continue to come to a stop, as long as I'm going very slow.

If I clutch-restart the car while still above 30-40 mph, the car will idle 'seemingly' perfect for a few seconds, then just die.
I can repeat it still rolling over and over again.
Everyone else with this issue complained of poor idle when idling, but my idle seems smooth and as though all is well when idling.

If I start the car, it will idle smooth all day so long as you don't rev it up and let it drop on it's own.

Once stopped and still running, it will idle the whole time like nothing is wrong.

Other clues are:
-My LTFT hovers erratically from +7 to +10 and STFT at -3 to +4 when I'm at part throttle, crusing 55 in 4th gear

-Car does not have idle problem until warmed up.

-All vacuum hoses are new, in place, and look good all over.

-I already checked for exhaust leaks and only found two by the muffler. Fixed them, no change. No other exhaust leak found. I checked the manifold, all over every pipe, junction, everywhere, no leak. Test was done with a powerful blower sealed to the tail pipe. (Worked very well btw! )

-When crusing or wot, exhaust smells of nox fumes. Other cars don't like riding behind me because of it.

-Fuel filter changed for maintenance. No change. Air filter and pcv are still new.

-MAF seems to read perfect and is responsive to all throttle changes on Torque app's graph.

- There is no smoke from exhaust, no power loss, no hiccupping at all. In fact, it runs amazing.

It just won't grab and hold idle on its own.

Sorry for the long read.
Thanks for any ideas.

Sent from my SAMSUNG-SGH-I527 using FF Mobile

Last edited by cheap sleeper; 03-20-2019 at 07:46 PM.
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