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Stalling when stoping AAN Urs

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 Post subject: Stalling when stoping AAN Urs
PostPosted: Wed Aug 12, 2020 8:54 pm 
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kickin' tires'n lightin fires
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New day new problem and im losing my mind lol.

When the car is warm and im driving coming to a stop the RPM will drop and want to stall if i DONT blip the throttle. If im turning it seems to make things worse.

Car drives great, pulls hard and makes great power. All issues are coming to idle. If im in neutral and rev the engine the idle catches like normal and does NOT stall. Does not even drop below normal.

Ive checked the following:

ECU fuses - good.
ISV - cleaned and good
TPS - correctly adjusted ( still could be bad though)
AC - does this with AC on or OFF. No significant difference
Fuel pressure - 65 psi Normal ( im running a Walbro 450 )
AFR - good. 14-15 idle and 11.3 to 11.7 under boost
02 sensor - tried 2 with no change ( not to be ruled out )
FPR - brand new holds VAC.
MAF - tried 3 ( all cleaned )
Vac leaks - no found ( vac normal)
Boost leaks - none found ( makes full boost )
Scan for codes - no codes with VCDS
N80 - works and functions
Trottle cable - normal, not out of place.
Dash pot - working, throttle plate not slamming shut
Throttle body - good and clean.
Battery - new good voltage.
PCV - working condition

Things im leaning towards as im totaly in the dark now are:

Fuel pump - it a new 450 but is out flowing the FPR. 65psi is high at idle and im wondering if its a problem. I do have a just over 1k KM on it now and it has been good up until the last week when this stalling started. I have ordered a new 255lph pump to see if that helps.

02 sensor - shot in the dark...lambda control works and AFRs are spot on. ( verified witn WB02) but ..... gremlins?

TPS - it clicks and i have no codes .... but again maybe its bad.

Vac leak - im tempted to pull the i take manifold off and just reseal it. It was off 2 years ago and was resealed then but who really knows.

MFTS - could this cause it to stall out?

Coolant temp sensor - i know a bad one will cause rich condition so im thinking im ok but what are the thoughts?

CPS - seems unlikely only because the car fires back up right away with 0 issues.

Sorry for it being long winded, really hoping for someone to be like " this happen to me, i fixed it by ......... " lol. Even just any good advice or a solid direction would be much appreciated

Thanks guys.

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1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Wed Aug 12, 2020 9:45 pm 
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I sprinkle rubber on my Cherios
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To my knowledge, it seems like you've already ruled out everything I'd have to suggest...

I think its safe to say the coolant temp sensor on the back of the head isn't the issue; AFR's would be out of whack and the car would have a hard time starting, but it doesn't sound like your having any of that.

Was the ISV just cleaned out or have you ohm checked it once up to temperature? I'm not sure of the specifications, but it wouldn't hurt to look if you haven't already.

Not sure if it could be at all related, but maybe somebody else could chime in... would a failing voltage regulator cause the car to not be able to catch the revs when depressing the clutch leading to stalling out?

Thats really all I have for you buddy. It seems like your already exhausted everything i wouldve checked.

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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Wed Aug 12, 2020 10:14 pm 
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kickin' tires'n lightin fires
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The ISV was just out and cleaned. It was pretty clean TBH but i did it any way. Im not sure the ohms but i can for sure check it and see.

I did read a post where a guy had issues similar to mine but not exact. He swapped out plugs and it was fixed. He had issues under boost to though, where as i dont.

Its rough when there really is not much else to look at in terms of what coild cause it.

Coil packs maybe? Another shot in the dark. Im on red tops

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 13, 2020 6:24 am 
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mach 2 with my hair on fire
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Location: Lethbridge Ab
I had the same issue with my 92 S4 years ago and mine turned out to be the TPS.
It had something to do with the closed throttle position. I remember it drove me
crazy for a while and it didn't always do it, intermittent problems are the worst.
Replacing the TPS fixed it for me.

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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 13, 2020 8:18 am 
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Location: CT
Yeah I vote TPS too also make sure your BPV is good and vacuum line running to it isn't leaking anywhere. Maybe check the moisture trap vacuum line connections too?

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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 13, 2020 10:43 am 
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kickin' tires'n lightin fires

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What plugs are you running?


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 13, 2020 3:50 pm 
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BPV apears to be ok. I took it apart and cleaned it out. Re greased it.

The vac line is silicone and is good. No leaks or loose ends.

Im going ro have to pull the TB to replace the TPS, the lower screw is stripped bad.

plugs are NGK coppers, gapped to .20.

Going to look at the charcoal canister tomorrow after work, foing to drive the car tomorrow and see if the BPV made and changes. Then on to the next thing. Lol.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 13, 2020 9:50 pm 
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kickin' tires'n lightin fires

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If by NGK coppers you mean. BKR7E's I'd change them out. I had them on a car and had boost issues / misfiring when warm. No stalling. Junk plugs. Multiple people have had similar issues to me when warm.

I've been meaning to do a PSA on this on QW (GreenMachine).


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Fri Aug 14, 2020 8:50 am 
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mach 2 with my hair on fire
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Location: Edmonton, AB
Only thing that comes to mind Kenny is have you actually pressure tested your boost/vac lines or are you relying on the boost gauge? A proper test would see 10% over design pressure with a hold, say 5-10 minutes, and if you're really pulling out all the stops then a smoke machine too.

As always, if you need any of my spares to diagnose LMK. I should be getting back home sometime before winter lol.

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Find me on Instagram @pry4sno

|| 2010 Golf Sportwagen TDI /// #farmenwagen
|| 2002 Dodge Ram 2500 24v Cummins 4x4 #bertancummins
|| 1992 80 quattro 20v /// Eventual AAN'd Winter Sled
|| 1990 Coupe quattro /// #becauseracecar

|| Spare parts for sale


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Fri Aug 14, 2020 8:56 am 
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20v90q wrote:
If by NGK coppers you mean. BKR7E's I'd change them out. I had them on a car and had boost issues / misfiring when warm. No stalling. Junk plugs. Multiple people have had similar issues to me when warm.

I've been meaning to do a PSA on this on QW (GreenMachine).



Not BKR7E. they are the 4554 PN plugs. I've tried BKR7E, but they dont work well.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Fri Aug 14, 2020 9:10 am 
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kickin' tires'n lightin fires

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Those are non resistored “race” plugs. Not saying they’d for sure be causing your issue but others have had suspected problems with them.

Not a good idea to run non resistored plugs on these cars as the electrical interference can cause havoc with some sensor readings.

https://forums.quattroworld.com/s4s6/msgs/363134.phtml


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Fri Aug 14, 2020 9:15 am 
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kickin' tires'n lightin fires
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I have heard that as well, ill see about getting a new set of FR5DTC plugs. that could be the issue, I never even thought of it TBH.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Sun Aug 16, 2020 6:39 pm 
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kickin' tires'n lightin fires
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Ive replaced my TPS with a spare, re greased my 007 DV, and rwplaced my TB gasket. Not sure but ive driven the car 3 times or so now since and tried to stall it the same way as before. No dice! The idle catches like normal.

Even drove around tonight with the AC on high in 30c weather trying to build up heat and get it to stall...but nope. So im not sure if the DV, TPS, TB gasket fixed the issue but for now it seems better. Ill keep driving it next week and see whats up. Hopfully i can report back that all is well after a week of driving.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Thu Aug 20, 2020 8:19 am 
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mach 2 with my hair on fire
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Well you could probably put a multimeter on the old TPS and check that against Bentley spec, but my money would be on the TB gasket. How old was it, and did it have any dry rot or stiff spots?

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Find me on Instagram @pry4sno

|| 2010 Golf Sportwagen TDI /// #farmenwagen
|| 2002 Dodge Ram 2500 24v Cummins 4x4 #bertancummins
|| 1992 80 quattro 20v /// Eventual AAN'd Winter Sled
|| 1990 Coupe quattro /// #becauseracecar

|| Spare parts for sale


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Fri Aug 21, 2020 5:46 pm 
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kickin' tires'n lightin fires
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PRY4SNO wrote:
Well you could probably put a multimeter on the old TPS and check that against Bentley spec, but my money would be on the TB gasket. How old was it, and did it have any dry rot or stiff spots?


Gasket was 10k Km old. No rot or stiff spots was properly installed and TB was torqued to spec. Gasket looked good when removed.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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 Post subject: Re: Stalling when stoping AAN Urs
PostPosted: Tue Sep 01, 2020 8:38 pm 
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kickin' tires'n lightin fires
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Its been just over 2 weeks now, and that car has not hiccuped once pulls no stalling and the idle is stable. No drops or "bogging".

Can say for sure it was the TPS, but that what i changed and these are my my results.

_________________
1994 Audi S4 Volvo K24-7400-630cc
2016 Jetta 1.4T (Daily Driver) Stock
2016 GTI (Wife's Daily Driver) Stock
2001 Audi S4 (Stg3- K04s) Gone, Dropped valve cyl 4

IF YOU CANT STAND BEHIND OUR TROOPS...FEEL FREE TO STAND IN FRONT OF THEM!


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