why my AFR's are high? sr20det

[norcalslider]

well i got hooked up to a wideband and did a few pulls...setup is weird but ok..vacuum hooked up to bov and wastegate the afrs where shit like 13 down to 11.9 running 4-5psi running lean which leads to detonation and that i dont want...2nd set of pulls where with the wastegate vacuum disconnected running 12psi at 11.7 down to 10.8 running good....so why is this?...i was just told that the DP has a hole in it and coverd by exhaust wrap and my guess is that would through it all off correct. and what is the correct timing for this motor?

[OBEEWON]

That doesn't seem high enough for detonation.

Which timing are you talking about? Mechanical timing? I think its 15* BTC. That could be completely wrong though. I'd have to look.

Edit:

I also dont understand why your AFR's were more lean at a lower psi. You sure that gauge is right?

[norcalslider]

i just dont get why the afr's changed so much when i took the wastegate vac line off..

yes the mechanical timing.

[norcalslider]

i know the wideband is correct and the boost gauge is good also its just straight air no electronics

[OBEEWON]

I guess I was right. Mech timing is 15* BTC. Check the FSM on how to stab the CAS. Set it to TDC and line the dot up with the first mark on the CAS and push in till it lines up with the second mark.

1. What modifications do you have to your motor? What engine management are you using?

2. You need to fix that exhaust leak. If it is anywhere before the last bend in the dp it can change the AFR reading not to mention sap power.

3. Also where do you have your bung reading your AFR's from?

[norcalslider]

Originally Posted by OBEEWON

I guess I was right. Mech timing is 15* BTC. Check the FSM on how to stab the CAS. Set it to TDC and line the dot up with the first mark on the CAS and push in till it lines up with the second mark.

1. What modifications do you have to your motor? What engine management are you using?

2. You need to fix that exhaust leak. If it is anywhere before the last bend in the dp it can change the AFR reading not to mention sap power.

3. Also where do you have your bung reading your AFR's from?

haha im new to this 240 stuff so tho's 3 letter words i dont know sorry.

the motor is stock just a turbo mani,screamer pipe and dp with a hole in it
the bung is down below in the dp right after the bend

i have no engine management

[JuMPiiN]

FSM- Factory Service Manual
CAS- Pretty much the distributor on a SR
TDC- Top Dead Center, search FRsport for the step by step guide to resetting it.

[norcalslider]

what am i looking for in the CAS?

[JuMPiiN]

Just go to FRsport and follow the guide to setting and timing it right..... You writing that tells everyone your lost.

[OBEEWON]

Take it to a shop or do a lot of reading and searching. There is lots of info on this site that will help you out if you feel like trying to diy.

[norcalslider]

i know what the CAS is now sorry guys ima noob and ill see what i can find on frsport

[norcalslider]

looked on frsport,looks pretty straight forward

[reshizzo]

hi,

my wideband show me 20 when it is in lean cruise
and 16 when i have boost pressure

why???

i have a sr20det with following:

gt28r (stock boost pressure)
big intercooler
3" exhaust (complete, turbo elbow, downpipe ...)
stock ecu
stock injectors
big apexi air filter

[reshizzo]

.......???.......... what for image?

[zurud]

Another blown sr20det coming from romania. INCREASE YOUR FUEL PRESSURE

[reshizzo]

with a regulator or a bigger fuel pump (walbro 255) ?

[greenwood]

lol probably both bro.