i have a wideband question/problem

[matt black]

i just started boosting. my problem is my afr is high. what i do is start the car and let it warm up to operating temp then drive down my road 15mph ..then i get to the main street

1st gear afr are good at 2500pm the afrs 12.0-12.5 and it stays like that all the way to 5500 then i shift into 2nd . in 2nd gear the afr is about the same 12.0- 12.3 . then when i shift into 3rd the afr goes straight to 20 and does the same in 4th straight to 19-20 .. all these reading where read at high throttle

i was thinking maybe the o2 sensor is heating up and effecting my afr readings in 3rd and 4th gear..

my setup

t25 on a bottem mount mani370cc injectors FMICTurbo XS bovSAFC ILC-1 Wideband o2 w/Dynotune GaugeAutometer Boost gauge3inch turbo elbow stock SR downpipe gutted cat2.5 exhaust all the way back to a high flow elcheapo muffler . came with the carboost : 7 psi


Modified by matt black at 6:36 PM 1/6/2006

[crzycav86]

where's the wideband sensor located? Does it have its own bung on the downpipe, or does it get readings from the tailpipe?

what are the safc settings?

[GEO]

if anything his timing is bad and its casuing pre-combustion?

[matt black]

i welded a bung for the o2 about 2 inches before the gutted cat... i am also running stock timing .. could th etiming be my problem.. what should it be ??

[matt black]

my safc setting are

-27 in the hole low map -15 in the hole high map

i am still new to tuning and i am getting the hang of it.. i am just freaked out about when it reads lean
Modified by matt black at 6:12 PM 1/7/2006

[matt black]

well i figured out that my dynotune gauge is not very accurate.. i hooked the lc-1 to my laptop and i got totally different readings..here is the my log. i shifted close to 5000-5500rpm's in each gear

[Jookmasta]

u should retard some timing i think but what does the lc-1 recommend for where the sensor should be distance wise from the turbo and in what position? ya ur graph looks jumpy. was this recorded at partial throttle or full throttle? full throttle meaning tps reading 100.

[matt black]

the manual says install the o2 sensor before the cat and mount it on the side or the top of the pipe.. yes this log was recorded at full throttle.. u notice in the log where i shifted, the afr drops to the 8's then straight up to the 15's .. is this normal??

[Jookmasta]

try recalibrating the sensor or wideband thingy. did u post this up on the lc-1 forums at innovatives website? let em know

[matt black]

i think the lc-1 is working fine bc i recalibrated it and got the same results. i just need to know if the log is ok .. i mean should it go lean when i shift.

[matt black]

i think i found an answer for my afr going up during shifting

EFI systems usually shut the injectors off during coast-down conditions (throttle closed and RPM typically greater than 1500 RPM). In this situation the engine just acts as a car-driven air-pump and fills the exhaust system quickly with pure air.

An excessivly lean condition. This condition can occur normally on EFI vehicles when the ECM turns off the injectors to save fuel during deceleration (known as DFCO, or deceleration fuel cut-off)
Modified by matt black at 11:09 PM 1/9/2006