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Lambda ratio and voltage in closed loop. http://forum.fordiag.cz/viewtopic.php?t=371	Stránka 1 z 2

Autor:	Bobson [ 07 čer 2016, 08:49 ]
Předmět příspěvku:	Lambda ratio and voltage in closed loop.
Hi, i am from Poland and i use Fordiag for several years. Previously, I did not pay to much attention but now something did not fit in the work of the lambda probe. I read a lot of tuning engines because it is only now pointed this out. In closed loop lambda ratio gauge in my opinion not working properly. When the voltage on the probe increases it indicates the mix of rich fuel, but in fordiag pointer lambda indicates a poor mix of fuel. Analogy, if the voltage at the lambda probe decreases it indicates poor mix of fuel but pointer lambda ratio shows the opposite. When a leak in the intake usually error pops up a lean , but the indicator lambda ratio indications show a very rich mix of . For example, some of my recordings https://www.youtube.com/watch?v=OZw1ZGlrJjs https://www.youtube.com/watch?v=rryojKFGh_o In my race car I have the fitted sport camshafts, after installation , of course, I had a problem with the fuel mixture. The program showed very poor mix of fuel and actually felt not burnt gasoline from the exhaust. After a while, I received an error "system to rich". Please check if this is a problem in the program , it is possible that this or just something I do not know , and so it has to be. Denies it but every little theory on labor lambda probe . Best regards (PS i am sorry for my poor english)

Autor:	Tomin [ 07 čer 2016, 10:39 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Hi, firstly, just for clarification: poor is not the right term, I think. I think the better term is LEAN mixing. I will use this term. Are you talking about second gauge from top of the screen ? This gauge is lambda voltage and should indicate >0.5Volt = rich mixing and <0.5Volt = lean mixing Is it so in your case ? First top gauge is not a lambda, but LAMBSE and this is another story. Are you talking about first or second gauge ? Just for speedup of debate - you can take and post some graph of EGO1 and LAMBSE1 values. It will be much clearer and informative on graph.

Autor:	Bobson [ 07 čer 2016, 13:28 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Hi, thanks for answer. My mistake with "poor mix" you are right. I talking about first gauge. On gauge is written lambda ratio LAMBSE. Lambse means desired AFR by EEC (at this moment)? If yes i think lambda ratio is not the same as LAMBSE. IMHO LAMBSE = desired by EEC AFR, lambda ratio = current AFR.

Autor:	Tomin [ 07 čer 2016, 14:07 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
LAMBSE is desired lambda ratio. We can speak about [lambda ratio desired] and [lambda ratio achieved]. It is a number what ECU would like to achieve in reality. This number is used in calculation how much fuel will be squirted.

Autor:	Tomin [ 07 čer 2016, 14:12 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Current lambda ratio is not known in systems without wideband lambda.

Autor:	Bobson [ 07 čer 2016, 14:51 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Always I thought that the top gauge indicates the current AFR. For this reason it was misunderstanding. Thanks for the explanation PS lambse means stft?

Autor:	Tomin [ 08 čer 2016, 11:53 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Yes, in meaning yes. Only there is a different in number expression. STFT is usually in [%], so 0% means no triming, -10% means -10% of fuel in mixing etc. LAMBSE is expressed like lambda number, so 1=stoich condition, <1 means richer cond. (more fuel than stoich), >1 means leaner (=more air)

Autor:	Tomin [ 08 čer 2016, 12:07 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Citace: Always I thought that the top gauge indicates the current AFR. Current vs. desired: on the ideal and 100% engine it is equal, but in reality would not be. It is important to understand that desired AFR is, in ECU, something very important (and very primary) in computation of fuel amount. Once you take some graph of LAMBSE (or STFT) and EGO voltage on engine in closed loop, you will see something like this On the start of trace: - if lambda voltage is high (rich cond.), LAMBSE goes higher and higher (= leaner and leaner) until lambda voltage drops down (started lean condition) - then LAMBSE starts go lower = against to richer and richer mixing and ECU "waits" for lambda to switch to rich condition See patent: http://www.google.tl/patents/US6550466

Autor:	vieplis [ 19 říj 2016, 15:38 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Citace: PS lambse means stft? Citace: Yes, in meaning yes. Only there is a different in number expression. STFT is usually in [%], so 0% means no triming, -10% means -10% of fuel in mixing etc. LAMBSE is expressed like lambda number, so 1=stoich condition, <1 means richer cond. (more fuel than stoich), >1 means leaner (=more air) Citace: ... Once you take some graph of LAMBSE (or STFT) ... on engine in closed loop ... LAMBSE goes higher and higher (= leaner and leaner) ... LAMBSE starts go lower = against to richer and richer mixing ... Tomin, I'm observing my vehicle ('2007 Mk4 Mondeo, 2.0 Duratec-HE AOBA) with ForDiag, which provides only LAMBSE and KAMRF values ("centre" at 1.0). Most of the available reference, troubleshooting and monitoring information online refers only to STFT and LTFT values ("centre" at 0%). In order to understand, compare and share my vehicle's readings, I would like to know if there a direct relation between ForDiag's LAMBSE/KAMRF values and other devices' STFT/LTFT values. 1) May I simply express my ForDiag's LAMBSE readings into % STFT, as shown below? ForDiag's LAMBSE 1.07 = other devices' STFT "negative 7%" (LAMBSE 1.07 = STFT -7%): ECU sees too rich => ECU desires to make leaner => ECU commands -7% of fuel in mixing; ForDiag's LAMBSE 0.95 = other devices' STFT "positive 5%" (LAMBSE 0.95 = STFT +5%): ECU sees too lean => ECU desires to make richer => ECU commands +5% of fuel in mixing. Correct? 2) KAMRF. ForDiag's KAMRF 0.90 = other devices' LTFT "positive 10%" (KAMRF 0.90 = LTFT +10%): ECU sees too lean => ECU desires to make richer => ECU commands +10%. Correct? 3) KAM adaptations map. For example, 12.5 % Load 1000rpm cell, green -10.0%. What is actually happening with this cell? ECU sees ~10% too rich => ECU desires to make leaner => ECU commands -10% of fuel in mixing; or ECU sees ~10% too lean => ECU desires to make richer => ECU commands +10% of fuel in mixing? Thank you in advance for response.

Autor:	Tomin [ 21 říj 2016, 11:20 ]
Předmět příspěvku:	Re: Lambda ratio and voltage in closed loop.
Hi, in 1, and 2, you are 100% right. ad 3, For example, 12.5 % Load 1000rpm cell, green -10.0%. What is actually happening with this cell? yes: ECU sees ~10% too rich => ECU desires to make leaner => ECU commands -10% of fuel in mixing;

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