After installing a light weight flywheel my car stalls occasionaly after slowing down. Im running a dezod turbo and the AEM F/IC - i have been tuning the car myself but im not sure how to stop these symptoms. My AFR at idle varies from 13.8-15.5 back and forth but averages 14.7.

Any ideas on how to make it idle smoother?

 

Doing some research found this video:
http://www.youtube.com/watch?v=U0R1K...eature=related

States the HKS Bov causes the stalling - sounds like my exact symptoms. Is it my BOV causing this or my tune?

 

I'm no engineer, but it could have something to do with lack of inertia due to the lighter flywheel.

But that's just a guess.

 

depends...is it stalling whenever you let off the gas?
Or only when you jam in the cluthc right when your in full boost?

 

I agree with the light flywheel thing.. but it was doing it before the flywheel as well ... now just more!

It happens nearly every time when i jam in the clutch when im in full boost... and it happens at least twicec a day just normal driving like backing out of my driveway or stoping at a stop sign. I notice at idle it doesnt just sit, it bounces around 500-1000 rpms for about a minute untill it settles in about 700.

 

When you jam in the clutch in full boost, it is DEFFINATELY the BOV. The synapse seems to fix that, as would getting your HKS recirced into your intake.

The bouncing at idle, that's tuning, and has nothing to do with yoru flywheel or your BOV.

My cruise AFRs bounce from about 14.2 to 15. If it's bouncing alot, your management is probably fighting with yoru ecu...you running the f/ic or the greddy blue?

 

come on mr. meaty - you know im running F/IC!

I dont know why it would be fighting with the ecu

My cruise AFR sounds the same as yours, its just damn idle!

 

that's what I thought, but i had to make sure!
my F/IC was fighting with my ECU because my 02 sensor was bad...aen's as well...

I should have a new map available for distribution this weekend...

 

Nice, ill send you my new map as well.

No check engine lights here tho so i doubt i have a bad O2.

 

...I had not CEL but had a bad 02...go figure...it was working well enough to not cause a CEL, but not well enough to work well with the f/ic...

 

wierd.. think a car with 12k miles has a bad 02...

im going to bring it back to the dealer for .... warranty

 

changed my 02 value on the F/IC map richer.. and now it idles much smoother.. but at 13 AFR. What is everyone else idling at?

 

it's the hks.

if you go to home depot in hte plumbing isle there is a fitting that looks like a screw type and if you grind down hte sides it fits right into the hks , then buy a tube and attach it to a welded piece on your intake pipe.

your idle gets a hell of alot more smoother and no risk of stalling.

 

oh. hahah ok

there are a couple different scenerios

1. o2 sensor is bad = fuel trims to go crazy and make hte scion ecu correct it by increasing throttle

2. fuel trims were bad from the get go - makes scion ecu correct everything by bouncing

3. vac leak.

if cruise is fine then most likely it's fuel trims because ruise is in closed loop..

watch for cel soon.

 

enjoithis, i was having the same problem as you and have spent hours working on just the tuning at idle. so far this is what has worked for me. at idle pull up the map and your gauges so that you can see what cell is highlighted when it is running. In the cell that is highlighted at normal idle put -25 in the ignition table, put whatever voltage corresponds to 15.0afr in the O2 table. and put -20 in 2 cells each direction of your idle cell in the timing chart. ie 2up, 2left, 2 down, 2diagonal. i haven't had my idle surge or stall in the last week since i did that. try it and let me know how it goes

 

I have the FI/C and HKS bov and my idle is completely smooth and i have never once stalled or even come close when pushin the clutch in full boost.

 

Is retarding the spark at idle the right thing to do or just a band aid?

My idle was pretty smooth untill i got the light weight flywheel.

 

you can make your idle richer, usually rough idle happens when it gets leaner than 15.. not sure how the aem fic software works though but try looking into the cell where your idle is at and try to adjust the afrs to make it smoother on the rich side, but that if you can do that

 

so what causes the F/IC to "bounce" .. when it idles at at 14.7 fuel trims are no more than 5% but the afr bounces between 13 and 16, even when on partial throttle it does the same, and you can feel it pull more when running richer. I need to tune this out!

 

fuel trims?

car trying to compensate for the lghter/faster rpm?