Subaru Impreza GC8 & RS Forum & Community banner

1 - 12 of 12 Posts

·
Registered
93 Impreza 6MT, White
Joined
·
170 Posts
Discussion Starter #1
Hi, My car recently is having a bugger of a problem in stalling in almost any stop sign when I drop clutch into neutral at stopping speed... is this the cause of my atm. HKS BOV screw or a setting on the SAFC such as deceleration correction or any pin points you all might know for engine stall on turbos?? Thanks.

-Vic
:stupid:
 

·
Registered
93 Impreza 6MT, White
Joined
·
170 Posts
Discussion Starter #2
The last thing I hear from it is the "cheeeew" sound from the HKS BOV before the lights on the dash come on...
 

·
Premium Member
Two Mini Coopers!
Joined
·
10,629 Posts
Well, in theory, a car needs three things to run:

1. Compression
2. Proper air/fuel mixture
3. Spark

So I assume you've got compression, since that's pretty hard to screw up, and I assume you've got spark since the car runs for the most part, but what you most likely do NOT have is a proper air/fuel mixture. At high speeds it doesn't really matter as much, since too much gas will just burn rich, not enough will burn lean (which, BTW, will destroy a turbo engine super fast because it encourages detonation). However, at idle speeds, a proper mixture is a killer. As is detonation - firing too soon as the piston is still moving upwards. So, one, can you smell gasoline coming out your exhaust when the car is running? If it's very noticible, then you have a mixture problem. If not, then things are probably okay unless you are not running enough fuel.

Now, all those things aside, you need to check for engine codes. I don't know how off hand, but I assume someone here knows, or call your dealer. If you have a bad sensor it'll tell you. A bad sensor can affect the mixture... voila that might be the problem. But don't just start replacing things, your car has a built in way to tell you what is wrong, so listen to it first, then start messing around. If all else fails, take it to a reputable shop and have them give you a diagnostic session.
 

·
Registered
93 Impreza 6MT, White
Joined
·
170 Posts
Discussion Starter #8
My SAFC shows that the sensor check on the MAF and TPS are in working order... how good I do not know... This problem of me stalling is when it tries to idle, especially when I rev it to around 2500+ rpms and all of a sudden stepping on the clutch pedal and brake... I have adjusted my BOV and that should not be the problem... I have also heard that Deceleration-Air correction is unnecessary on our Subarus... there a re no obvious vacuum leaks neither...

my thought now is... I am debating of whether my safc setting is making it too rich for the motor to properly decelerate to idle... perhaps most likely an issue of flooding the engine with too much fuel when travelling to the low 1000rpm zone? I will try to tweak the corection to see if this will work...
 

·
Registered
93 Impreza 6MT, White
Joined
·
170 Posts
Discussion Starter #9
SWEEEET. After setting my sensor type back to HW-10, my cold starts is like new (or stock anyways...), it can successfully do a rich fuel cold start while successfully lowering the rev from 1500rpm all the way down to operating temperature (700-750 rpm), and I tried turning on the AC at that point and it revs up to 850rpm to run the AC... it works great again... I am suspecting the stall is also due to a rich fuel adjustment done on the 'LO' rpm setting... it was correcting a +7% on 2000rpm, and that was probably one of the reasons why it shut off or fuel flooded in my opinion. I have disconnected the battery again, and will go see if my stock 0% correction from 1000rpm to 3000 rpm on 'LO' setting will fix the problem of my arse stalling when I blip from 3000rpm gear to clutch out into neutral to brake... I really hope that is just a simple (yet such a PITA before I figured) issue of too much fuel when decelerating... :barf: I will whack myself in the head by running very fast into the wall if I blew one of my sensors, for god sakes, I only boost max 5 psi and only around 0.5% of the time when I drive, thats just sorry if that happens.

-Vic
 

·
Registered
99 2.5 RS-T
Joined
·
838 Posts
You're running a 100% atmo BOV on a 99? I've heard it can be done but why not just recirculate like you're supposed to? The air has already been metered by the MAF so you're going to run pig rich when the BOV releases. My comment on plug fouling was hinting at just that. If you're set too rich in the first place and you're venting to atmosphere my concern would be too much fuel in the cc and fouling the plugs causing your stall. Anyone?
 

·
Premium Member
Two Mini Coopers!
Joined
·
10,629 Posts
Yeah, if you are running a 99 you really should be venting back into the intake, not to atmosphere. That will cause your problems with improper mixture. Do it wrong and get detonation, and you can kiss the pistons goodbye.

I'd personally vent that sucker back into the system for safety.
 

·
Premium Member
overdeveloped beater
Joined
·
8,335 Posts
My first guess would be to put the MAF after the turbo and after the BOV. I don't think there'd be any problem with the heated/pressurized charge going through the MAF body. Any air vented to atmosphere would not be measured by the MAF and fueling shouldn't be changed that much. I've never heard of anyone in the Subaru world doing this, but I see no reason why not....

As for the SAFC settings, the Lo settings sound way high. During decell, you're under vacuum, so correction should be 0% or lower. If the turbo isn't making boost until xxxx RPM, then richening should not be needed.

I would stay very near 0% on the Lo side and richen things more in the Hi settings where you're going to need it.

Very generalized, but the basic idea is there.....
 
1 - 12 of 12 Posts
Top