Focus Fanatics Forum banner

MAF volumetric efficiency

1443 83
Rectangle Slope Font Plot Screenshot
1 - 20 of 26 Posts

· FF Affiliate
Joined
·
33,174 Posts
Then why did you say " To make sure its rich at WOT "

The o2 does nothing at all at WOT on pre 2012

.93 Lambda on your o2 means there is something wrong some where

Not offering and never mentioned anything about Tuning

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
You guys are wasting your Time , he knows what he knows and acts like its Fact but its only what he thinks he knows , He wants to run his Engine that lean after being warned its SUPER LEAN then let him !

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
So whats your point other then you dont like me and the Info I post even tho many others in this Post and the other names you have been kicked off here using have told you are incorrect , I see at least 5 people telling you your WRONG but you keep at it , why even come here other then to still the pot ? Your never going to Tune your Focus anyway , If you even have one and I would bet the pictures you posted of the graph are from the Internet some where and you didnt do them , No Focus EVER had a WOT Lambda in the .9 range like the graph you posted does , If thats the type of Tuning you want is from youtube then go for it , stop asking in here , getting correct answers then arguing and trashing the people helping

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
My MK1 has a narrow band upstream O2 sensor. It reports voltage only. No lambda. Where you got that idea, IDK.



I posted my VE test graph and explained it. I didn't ask a question. Uninvited, the busybody people barged in with their unsolicited useless advice.
You posted a graph it shows 02SS11 This breaks down to O2 Sensor Bank 1 Sensor 1 , its shows at WOT .93 that is NOT Voltage that IS Lambda , As you can see in the graph YOU posted that you know nothing about obsessively, you can see it go up when you go WOT and down just after you let off , When WOT your in Open loop , that reading you see if whats in who evers Tune under your Open Loop Fuel Table as a Targeted A/F , it doesnt actually show A/F it shows what your WOT Open Loop Table is in the PCM settings which is .93 in A/F = 13.6 to 13.8 which is far to lean for any Engine under WOT , The reason it shows your in the Tune/PCM WOT Open Loop A/F settings and not Voltage or actual A/F is because it can no longer read fuel trims ( closed loop ) because your now in Open Loop being WOT and it basically turn off the trims and shows the PCM what its Target A/F is

You should know this but I am sure you will say I am wrong , I have only Tuned over 6000 Focus and many other Cars , I know how the Ford system works , you should do a lot more reading on Open Loop and Closed loop and stop watching youtube

Let the insults and Trashing begin

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
So much disinformation. The only way to stop it would be a user block feature. Without it, the busybody people run wild.
A better way is for you to just stop posting misinformation ! ! ! !

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
I bought the car new at the dealer and owned it ever since. It's never been modified or "tuned." If the factory got it wrong, it's been that way for the last 20 years. That's hard to believe.

If what you say is true, It should have exploded by now.
These comments truly tell me how little if anything you know about Tuning , I gave you all the info you needed and come up with why its like it is at .93 and all you have is it hasnt blown up yet , how can you argue with anyone on here about Tuning if you dont know the basics ... I know , Just to argue !

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
Ah so interesting on the Tempo piece. It's been a LONG time since I've driven one of those.

MAF is nice once it's dialed in, OEMs have all that time and money to get it done. For beginner tuners (me), I like the MAP based stuff because it's easier to get a car running decent. It's easier to understand with little background (I can understand what KPA is, it's harder to "understand" what load is without having more tuning knowledge). Reading and learning more tuning theory, MAF starts to make more sense and you start to see: 1 - Why OEMs use it 2 - Why it's more accurate and 3 - The methods pro tuners use to dial in MAF transfer quickly and how to calculate the Lambda adjustments needed vs guessing or blanket adders.

Greg Banish's books on tuning have good examples right from SCT PRP to show how to tune a variety of these tables, and the theory as to why.
If you watch a Vac Gauge ( MAP ) and drive and watch a MAF Curve and drive you will quickly see why MAF is more real world and more accurate to how the Engine/Air is working , MAF is far more accurate for daily driving NA or Boost , cars that do Racing with Boost or a lot of OEM boosted cars use MAP because it sooooo much cheaper to design the software , I dont like the way the ST or the RS drive and with a little work on a few things MAP related you can get them to drive much better but never as good as a MAF Tune

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
Earlier you said those numbers are too lean for WOT. You're not making sense.
I said YOUR Numbers were to lean , the Numbers in Blue/Red are 45% TPS WOT Fueling and I have WOT Open Loop TPS % Set to 55% to go Open Loop Fuel , Now taking all that into the Mix that .834 does not mean his Open Loop A/F Fuel will be 12.4 the PCM / ECU also factors in Maf Transfer Functions as well as ECT , IAT and about a dozen more Factors but they have little bearing on the final A/F , Its Mostly the Open Loop Tables and Maf Transfer Functions

What shocks me is you dont know that the Narrow Band 1.0 Volts/Lambda = 14.7 Stoich and .83 Volts/Lambda would be 12.4 +/- A/F

You dont know what you dont know and you shouldnt always argue with those that do , I dont know everything but im pretty good at what I do contrary to your beliefs

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
You still want to argue about everything , I cant help you ... No one can you figure it out doesnt matter what I say you want to argue and make snide comments like " If I can " lol again wouldnt matter you would say its wrong , good luck

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
If that PID is narrowband voltage, someone correct me if I'm wrong but ~0.5V = 1 lambda. Once you deviate from stoich, the voltage really only tells you if it's richer or leaner, not by what magnitude. The sensor is accurate at stoich.
No one is taking into account that at WOT ( Open Loop Fuel ) and the WOT part is what I have been talking about this entire time ,the O2B1S1 is turned off , it cant just shut off so it will mimic whats in the Table I posted ( Base Fuel Table ) regardless of what the actual A/F is , That isnt Voltage in that log at WOT

And yes hEaT you are correct .5 = 1 Lambda , The o2 does tell you if its richer or leaner and by what magnitude if you watch the STFT1 which is the voltage to Lambda conversion " thats where I messed up here and have no problem saying when I do " That tells you in Lambda by what % its off , STFT1 sais .90 then you adjust by adding 10% , 1.10 you adjust by taking out 10%

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
I am talking about the WOT the pink line shows .88 the entire WOT

Rectangle Font Line Slope Parallel



Light Computer Screenshot Font Rectangle

Red line is TPS showing WOT
Dark Blue line is STFT mimicking the Base Fuel Table , If that was voltage on your first Pic at .9? you would be in the 10`s A/F and your NA Engine wouldnt run
Light Blue is A/F

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
Actauly that is from a 2003 ZX3 2.0 Zetec Narrow Band , Your 100% correct Narrowband 02 does not measure A/F in WOT Open Loop Fuel , the Narrow Band o2 when you go into Open Loop Mimics/Reads exactly what the Base Fuel Table shows just like the screen shots I posted , If I was to change the Base Fuel Table to go richer at say 4000 and richer again at 5000 and richer again at 6000 it would all shop the change in the Base Fuel Table in the log and STFT1 would copy/mimic the Base Fuel Table in the graph like I posted above

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
NBO2 DOES measure O2 WOT.

BUT,
The PCM does not use it. The reason it isn't used is as I stated earlier about the switching/frequency of the measured values being more important than the voltage output. In high exhaust flow situations the NBO2 can not switch fast enough to be reliable. Therefore it's not used for PCM input.
I would have to test that , I will log NBO2 Voltage on one and see but I think its going to show that the Voltage reverts/mimics to what the Base WOT Fuel Table is not what A/F is or what the A/F Voltage would be compared to a A/F gauge , I think doing this keeps the PCM from trying to make any changes from the NB02 , I will see

I know the NB02 has no effect at all on the final A/F Calculation

I know 100% for a Fact the STFT1 when in WOT mimics the Open Loop Fuel Tables with NBO2

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
Again , I am talking WOT Open Loop , your Talking off throttle Closed Loop where yes it does to 0 because your now in Decel Fuel Tables / Fuel Cut and again the NB02 isnt used

There is NO closed Throttle Open Loop , Open Loop is determined by Throttle Position , Once you go below above X Throttle Position ( For the ECU Code above stock OL TPS Open Loop at 3000 is 650 % TPS and at 4500 ,430 TPS to switch to OL , Below those TP is Closed Loop ) you go into Open Loop , Once you go Below X throttle Position you go into Closed Loop , your arguing about things you dont have a clue what your talking about

And again , I am talking about the OL

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
My graph disproves that near the 20 second mark. I went no throttle for a few seconds, to slow down.
Because you dont understand whats happening doesnt change the Fact of how it works 0 volts would be anything above 15/16 A/F I think it is and when in decel you will see 18`s A/f , letting off the throttle your in Fuel Cut / Decel Mode , there is no off throttle Open Loop , Open Loop occurs 2 ways , when you first start your Engine and when you exceed the TPS % set to go Open Loop WOT , There is no closed Throttle Open Loop

Tom
 

· FF Affiliate
Joined
·
33,174 Posts
That may be so but in this case I disagree, the diagnosis fits your general behavior to a T.

From your own link, which you have disregarded in certain parts to even now be guilty of said thing......

'Passive-aggressive behavior is characterized by a pattern of passive hostility and an avoidance of direct communication.[1][2] Inaction where some action is socially customary is a typical passive-aggressive strategy (showing up late for functions, staying silent when a response is expected).'

That's you or I ain't me. You endlessly post links as 'proof' but most of the time they blow your boat out of the water.

We understand your disdain for reality being it is so inhospitable to you.
Just felt this needed repeating , amc49 you sent this to bcat loved it LOL

Tom
 
1 - 20 of 26 Posts
Top