Mag's OSE 12P Thread

[Holden202T]

heres a log of my o2 sensor

[mag]

Interesting, my o2 sensor may be not as crazy as I thought. Everything I read or see describes a pretty clean sinewave pattern & anything else is considered a dud. Even on a steady cruise I would not call my pattern a sinewave, just cyclic with the period shortened or extended depending on how steady the load.

Have a genuine 2 bar MAP as a reference that I have used on occassions but logs for it do not show dramatic difference to diy. Have logs for all three that show min kPa seen as: factory 1 bar is mid 20s, factory 2 bar high 20s & diy mid 20s. However easy enough to change & see what happens.

I get high 30s, low 40 kPa. What is typical value for idle?

[Holden202T]

30-40kpa at idle depending on idle timing...

you need to change your monitors so they display in different colours, too hard to read whats what there.

[VL400]

Your O2 sensor does not seem to be getting that many cross counts compared to a healthy one. What sort of cross count numbers are you getting? I would be going back to a pre-ve learn cal, turn VE learn off and log the BLMs.When using VE learn do what yoda69 suggested and disconnect the carbon canister, it will skew the learn a fair bit.

If you want to compare yours to the genuine, hook up both MAP sensors and log them. Use either sensor on the normal MAP input and then use the wideband input for the other. Change the wideband config in the cal so it does no conversion and in scannerpro change the widband calc to that of a 2 bar MAP sensor. Overlay both sensors on scannerpro monitor and see how close they are.

[mag]

VL400, lots of good suggestiions I will work through but need some help.

With the o2 count question. I get numbers 1, 2 or 3 but they just appear random & then resets to 0 for longish periods, never a consistantly high count number. Is count value = number of o2 transitions in a given period.

May be if I confess that o2 sensor is original some 390,000 km old, you are going to say "change it". Have read that o2 sensors can go slow when they get old, not necessarily fail out right. Could be my problem as although sensor cycles <300mV & >600mV, it still may not be giving good feedback.

Regarding vacuun cannister discussion, are we saying a dud cannister would stuff up ve learn or that any vapour return will cause a problem for ve learn. If the latter is true that means I cannot ever use the factory cannister setup with ve learn. Also if ve learn is affected by cannister vapours, would not BLM mode have the same problem.

[Holden202T]

o2 cross counts is the amount of times it swings from rich to lean, the higher the better, and the less there is the more lazy your sensor is .....

i've seen stable cruising show 10-15 cross counts so if your not getting somewhere near 10 you've probably got a dodgy sensor......

[yoda69]

Regardin canister purge and BLM's, that is part of the reason for the BLM's.
The BLM's can also be affected by fuel density, air cleaner efficiency, etc. and are used by the ECU to self tune.

[mag]

Yoda69, understand that dud canister can cause BLMs to be stuffed up. However why would I disconnect it when in ve learn mode, is your "disconnect the CC" comment only related to testing to see if the canister is a dud & thus adversely affecting ve learn.

Have a spare two wire o2 sensor that came fitted to the extractors, will give it a try & see if the number of cross counts increases. Any confirmation that o2 cross counts is the number of rich/lean transitions per some unit of time, just so I understand .

VL400, a little help for the amateur to setup for second map sensor. Only WB cal config I can find are "wideband 5v AFR" & "wideband 0v AFR" or I have I got the wrong cal config parameters. I remove calculation for which one or both? Also which pin is dedicated to WB input.

[yoda69]

The amount of vapour (fuel) in the carbon canister can vary from drive to drive.
ie. Full tank, empty tank, hot day, cold day, 91 Octane, 95 Octane, Summer fuel , Winter fuel, length of drive, etc. all affect the anount of vapour present at any given time.
Probably not as much of a problem on the pre VS stuff where it is activated by engine vacuum and possibly inactive at idle (maybe someone else can confirm), but on the later stuff there can be carbon canister purge at idle, which can have a large affect on BLM's.

It is just one variable that could be affecting BLM's, the holden manual states that +/- 10% is considered normal variation for BLM's.
It's probably best to talk with Holden202 and VL400 on this, as I haven't had a chance to play with VE Learn yet, as I've been working more on understanding the MAF based setups.

yoda69

[VL400]

Yoda69, understand that dud canister can cause BLMs to be stuffed up. However why would I disconnect it when in ve learn mode, is your "disconnect the CC" comment only related to testing to see if the canister is a dud & thus adversely affecting ve learn.

If the CC is affecting the AFR then its working, the vapours will cause the AFR to be rich when vapour is drawn in from the CC. Try this for more info ... http://tinyurl.com/33wc9ve

Have a spare two wire o2 sensor that came fitted to the extractors, will give it a try & see if the number of cross counts increases. Any confirmation that o2 cross counts is the number of rich/lean transitions per some unit of time, just so I understand .

Confirmed, the number of cross counts per 100mS.

VL400, a little help for the amateur to setup for second map sensor. Only WB cal config I can find are "wideband 5v AFR" & "wideband 0v AFR" or I have I got the wrong cal config parameters. I remove calculation for which one or both? Also which pin is dedicated to WB input.

Make the 5v AFR = 25.5 and the 0v AFR = 0. Then in scannerpro or tunerpro ALDL definition change the wideband calc (currently X/10) to the 2 bar MAP calc of (x*0.781) + 8
See here for pinouts .. https://pcmhacking.net/forums/viewtopi ... =356#p3833