VEMS Community Forum

VEMS => Configuration => Topic started by: Tcal on December 22, 2007, 05:53:51 PM

Title: WBO2 Heating
Post by: Tcal on December 22, 2007, 05:53:51 PM
WhatÃ,´s the recommended heating time to that LSU4 sensor?
If that time is too short, will it cause problems like false reading or something?
Title: Re: WBO2 Heating
Post by: dnb on December 22, 2007, 10:48:24 PM
I use 25 seconds.  It seems to work OK.
Title: Re: WBO2 Heating
Post by: Tcal on January 01, 2008, 09:20:48 AM
IÃ,´d like to hear others comment on this too, anybody?
What are your experiences on this, iÃ,´ve read somewhere that normal ecus heat that LSU about 20 secs??
Title: Re: WBO2 Heating
Post by: [email protected] on January 01, 2008, 01:24:49 PM
The sensor's heater is monitored and a reading is not given until it reaches its operating temperature.
Which warm-up time setting are you thinking of?
Title: Re: WBO2 Heating
Post by: Tcal on January 01, 2008, 02:56:21 PM
So if i set it like 2 seconds, it wonÃ,´t give me any reading before itÃ,´s heated properly and is giving correct value? correct?
Will this cause problems?

I have that time set to 40 secs now.
Title: Re: WBO2 Heating
Post by: [email protected] on January 01, 2008, 04:07:52 PM
Where are you setting this?
Title: Re: WBO2 Heating
Post by: Tcal on January 01, 2008, 04:43:39 PM
Settings -> EGO control -> Warmup time.

Hmm i did think this again..
That doesnÃ,´t change that O2 heating, itÃ,´s the time when vems starts to show/use lambda ?
ItÃ,´s the warmup ramp in settings -> wideband settings, that changeÃ,´s that heating time ?
Title: Re: WBO2 Heating
Post by: [email protected] on January 02, 2008, 02:03:47 PM
Leave the wideband settings alone! They should be setup as per the instructions here: http://www.vems.co.uk/forum/index.php?topic=55.0
As for the EGO value - 60seconds is usually enough.

Cheers

Rob
Title: Re: WBO2 Heating
Post by: Tcal on January 03, 2008, 09:37:23 AM
Those WB settings are bit modified by the previous owner:

fallback V after maxt is 96

Pump KP 64
Pump KI 46
Pump KD 8

OtherÃ,´s values are as in instructions...
I donÃ,´t know the reason why those are changed.
IMO are those pump settings more aggressive than factory or how would those make difference?

And what does that fallback change?

Maybe i should try those "original" settings too and see if that lambda behaves differently.

And the reason why iÃ,´d like to set that EgoC on as fast as possible is because in cold weather like today (-28c) engine doesnÃ,´t run as it should when warm engine is started and that IAT looks like -14. No problems usually in norm temperatures.
Title: Re: WBO2 Heating
Post by: [email protected] on January 03, 2008, 10:04:10 AM
Use the suggested PID settings, these are the ones that have been developed specifically for driving this sensor.
What do they change? I cant honestly say as I have very limited knowledge on the way the Pump and Nerst closed-loop control actually works.

Its going to take an amount of time to get the sensor hot enought to provide a correct reading, no matter what you do.

If you are having problems at lower temperatures then this is really a cold start enrichment issue rather than the way the sensor is being driven - chances are you're way too lean.  Although this graph is for crank fueling it does show how the fuel requirement increases massively with small temperature changes as things get colder - note the difference in fueling between -15 and -25
(http://www.vems.co.uk/VEMSUserManual/CrankFuelling.png)