Safcii

[Rocky213]

Need help with tunning my 92 talon tsi. Has full 3' exhaust, MHI evoIII 16g turbo,SAFCII,Wideband. having trouble tunning the SAFC. did a couple pulls in 3rd and keep getting around 9 reading on the WB. Adjusted the fuel down numerous times to about -35 from 3000rpm-7000rpm. Still getting the same #. checked fuel pressure at the AFPR to 40 w/o vac hooked up. starting to get frustrated. can someone help me

 

[PotatoFlakeSTi]

Need help with tunning my 92 talon tsi. Has full 3' exhaust, MHI evoIII 16g turbo,SAFCII,Wideband. having trouble tunning the SAFC. did a couple pulls in 3rd and keep getting around 9 reading on the WB. Adjusted the fuel down numerous times to about -35 from 3000rpm-7000rpm. Still getting the same #. checked fuel pressure at the AFPR to 40 w/o vac hooked up. starting to get frustrated. can someone help me

Do you have any way to log?

 

[Rocky213]

no..dont have a way to yet

 

[compression]

Do you have a walbro 255? what kind of regulator do you have? Sounds like a boost leak. What is the richest the WBo2 will read? could it be 9:1? what size injectors does the car have?

You should update your mods list before asking tech questions. I will do what i can to help you.

 

[Rocky213]

yea i just updated it. but running stock injectors, not sure on the fuel pump. guy i bought it from said it was rewired thats it. was geting 9.1 also 9.4 on WB reading. all pulls i was getting low 9's

and only about 12psi of boost

 

[PotatoFlakeSTi]

Lets start off easy then.

9.X AFR, extremely rich....
Did the car feel low on power?
Was there an extreme smell of unburnt gasoline?
Was there a giant plume of black smoke behind the vehicle?

 

[stacked1G]

i wouldnt think you would need such extreme adjustments still being on stock injectors. you shuld really get a way to log. also are you sure the WB is accurate? like above poster said are you seeing any of those symptoms? im not 100% on using an afc cause i never have, but how are your fueltrims looking? is it at 14.7 during idle?

 

[Rocky213]

it feels like it has more to gain but it reads 9x or so around 12psi and i back out of it. not sure about the smoke out the back. kinda figured it was running rich. adjusted fuel in the 3000-6000 rpm range down to -30 to about -35. but only getting to 4-4.5 rpm and im reading 9x

15 @ idle

 

[PotatoFlakeSTi]

it feels like it has more to gain but it reads 9x or so around 12psi and i back out of it. not sure about the smoke out the back. kinda figured it was running rich. adjusted fuel in the 3000-6000 rpm range down to -30 to about -35. but only getting to 4-4.5 rpm and im reading 9x

Alright, so we've got no idea if it's actually running rich or not, just that the gauge indicates that it might be.

You'd probably smell it.

If you've made sure you have no vacuum/boost or exhaust leaks, my next bet would be a faulty wideband sensor.

 

[Rocky213]

did boost leak test. have no leaks as far as i can tell. yea im gonna swap out the sensor and see what happens. i really need Dsm link

 

[clipto]

So I had your setup well just about the same and with the safc you can only fool the stock ecu so much. Without a logger I would not go to far just try to lean it out a little sence stock a/f ratio is like 9:5 I was able to lean it out on the safc to like 10:1 and you can feel the power but best would be around 11:1 a/f ratio. But remember you will be on stock timing map for the ecu and you won't know if your knocking, every car is different. But definitly if you lean it off a little from the stock a/f ratio under wot you will feel it pull alot better making some power. -35 is way to low of a number are you do hi or lo thrttle settings? Are you on stock injectors and what psi are you boosting right now? Look into getting some logging software so we can see whats going on.

 

[compression]

I believe the stock 1g afr is what..9.8:1 ? Which you aren't too far off from but that isn't including the adjustments you've allready made. Do you have a CEL ? where is the wbo2 located ? Is the stock o2 sensor still there ? Could you have an exhaust leak ? Try to lower fuel pressure regulator 5lbs and see whT the afr reads you have a lot of wiggle room being at low 9's

 

[Rocky213]

the wb o2 is about 4 foot from turbo and the other is on the o2 housing. gonna try to adjust afpr and see what happens

 

[compression]

4 feet.. wow I would plug that hole and get a muffler shop to weld a new bung closer I think 2 feet is the furthest you'd want it. Not sure how accurate it is being halfway down exhaust .. I know that dyno shops put it in your exhaust tip but it just doesn't seem to be as accurate there

It's not after a catalytic converter is it ?

 

[1996tsitalon]

what are your throtle points at? also are you only tunning hi throtle points?

 

[Rocky213]

its b4 the cat ,but i have no cat.

1000,2200,3000,3400,4000,4500,5000,5400,6000,6500,7000 yea only adjusting (HI) messed with the lw settings but adjusted them back to previous settings

 

[compression]

Throttle points are like 30% low , 70% high or something like that , I believe he was refering to.

Did you adjust the fuel pressu regulator ? What did it say ?

 

[Rocky213]

throttle points at 30 and 80 fpr at 40 no vac hooked up then down to about 30 w/ vac

 

[chaclark83]

is the safc even installed correctly

 

[compression]

Set it to 37 psi unplugged. That's stock. Then go from there. If the Afc is reading Hz it should be hooked up properly.

What was the afr before you adjusted anything ?

 

[1996tsitalon]

I have my throttle points at15% low an 80% high.an my cars a/f was low like that when i was only adjusting high throttle
after i tuned in my low throttle it was alot better.my low throttle i was running -5 or so across the board high throtle was -30 to about -35 across the board.

 

[clipto]

Hey rocky what size injectors are you using?

 

[compression]

Stock, you should not be reducing your fuel by 30% with stock fuel Injectors. There's another problem somewhere , check for boost leaks again but check your pvc valve as well , or try capping it off and do a run.

 

[chaclark83]

Man I'm telling you. Something is BAD wrong. There's no way you can reduce mas signal 30+ percent and not make any changes to the wideband. Even with a boost leak. You have to have a faulty connection somewhere. Please wisemen back me up on this. 30 percent plus is crazy to not see any difference at all. Its either a bad reading from the wideband or you're not really changing the signal. in all honesty unless you had an ic pipe completely off with the 50 percent change that the safc offers you should still be able to make a difference in how its running. I understand the widebands have their limits with what they can read but I mean come on. If it was rich enough that a ratio that low was present it would foul plugs. There HAS to be a problem with either the wideband reading or the safc. Maybe they have the signal wires on the safc crossed. Its not hard to do, its only two wires. There's no need to start checking everything in the book. If the safc and wideband were working properly you should immediatly see a difference at 30 percent negative. Here's an idea. Safc work in real time so go into your low throttle settings at idle with a 1000 rpm point and turn it all the way down. The wideband should show leaner and the engine should struggle to run. It won't hurt anything. Its only idling. If the engine runs different but the wideband doesn't chang there you go. Wideband is junk. If the wideband doesn't change and engine function doesn't change then safc isn't working.

 

[bryanwheat]

^ This. The safc should be nearly zero'd out with stock injectors. If you have 30 percent pulled than the safc isn't working or or it is wired up wrong. The car likely wouldn't even run with that much fuel correction. I would just take the safc out and reconnect the maf signal wire. There is really no need for it with stock injectors in the first place.