StickyMicky

1.1 bar boost @ 5500 rpm in 5th gear
brand new lambda sensor showed 0.855mv

boost was tailing off as the revs rose

spank you in advance

Bob Rawle

What Model Year of car ?

bob

StickyMicky

97 wrx

TopBanana

The sensor could be way out, but that's 12.5:1. They like somewhere between 11.5:1 to 11:1 apparently.

Bob Rawle

Yes it is way too lean IF the sensor is reading correctly, however if you are very overfueled it is also symptomatic of being too rich. What is it like across the whole rev range on wot ?

bob

stevebt

iTrader: (8)

is it not due to you running that tdo4 for too long

mr smash

my 96 wrx does about the same on WOT this registers as rich on an electrosystems lambda link...on a impreza specific AFR this only registers as amber[althouhg when 1st warmed up i get blue or green light for the 1st couple of WOT blasts but dropps down 2 amber after a while.[amber=.83v-.85v]i have both units wired in.

is yours a uk or wrx?as we came 2 the conclusion on some past threads that cars with the lambda in the down pipe read richer than the ones with it in the headers[although this is just based on a few examples of voltages given and is more hypothetical than fact.

StickyMicky

i rechecked it tonite

it was .875mv although this was after it had been driven for about 10 mins on a dual carrigeway
i belive the lambda sensors start to read low after a while "on boost"?

the sensor is brand new
i have seen as high as .915 for a moment while putting my foot to the floor in 3/4th gear @ 3000 rpm

genraly driving about and not ragging it (holding it in high gears on boost for a while) sees a constant .895 or there abouts (the scoobymonitor rounds the figures down iirc)

[Edited by StickyMicky - 12/29/2003 12:10:38 AM]

StickyMicky

and it was boosting a bit to high for me on the way home as well, i saw 1.32bar on the scoobymonitor (takes its reading from the select monitor port/ MAP sensor i belive)

i will reset the boost to 1.2 bar tomorow and do a further test

Bob Rawle

With those numbers its "ok", allowing for the lambda sensor, try this, cruise at relatively low revs to get the egt's down then , in fourth, do a wot run from 1800 rpm and monitor the voltage, you need to read the true output as opposed to anything that is averaged or scaled so stick a meter on the signal wire at the sensor to eliminate volt drop, or measure the volt drop and factor that in.

Bob

StickyMicky

thank you
i will do this tonite when the roads are quiet

StickyMicky

i couldnt find my meter

so i did the test with the scoobymonitor

2000 rpm in 4th gear and held the throttle down
lambda sensor showed about .815 at first then .836ish and then when it came on boost it shot up to .895 and it held that figure all the way till i backed off @ approx 6400 rpm

Bob Rawle

Then thats fine, it wouldn't take much to send it too lean though.

Bob

StickyMicky

thats pretty cool as it was running a smidgen under 1.3 bar peak
cheers