i have been tuning on this stang for a while it is a stock 2016 with a vortech kit stock pulley auto car and has been running great doing whats its supposed to until we put a boss 302 and jba long tubes on it i deleted the imrc, the rear o2s and the evap.....
now the car is commanding insane amount of fuel took a sceen shot any one know wth is going on
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thanks for the help
Fuel trims are adding as much as possible to try and achieve stoich. It's commanding .61 Lambda to try and bring actual lambda to 1.0. Either huge vacuum leak or MAF cal is way off. Check injector O-rings. They like to stick in the stock intake manifolds.
Low vacuum at idle is also another sign of a leak.
MAF at 800 period. Either thats a massive intake pipe or you have a large leak and air is not having to go through the intake tube.
it's a stock vortech kit I think the tube is 4" bottles down to about 3.5 at the throttle body car is pulling 21" of vacuum at idle on boost/vacuum gauge
Am I wrong to assume that the car was idling at 1.03 but commanding .6 lambda
That's how I read it
Thanks for help
The command has control over fuel not air. When its commanding .6 its commanding more fuel. Its goal is to get the actual to 1.0. It means the engine is getting a lot of metered air. if you are getting good vaccum in the manifold the leak would be between the MAF and throttle body.
It could also just be a bad MAF or the tube the MAF is in was put in backwards, if thats possible on that kit.
The car is commanding .60 to get it to idle at 1.0. If the car was running correctly and is now this far off without increasing the MAF tube size by about 2", this car has vacuum leaks, or major exhaust leaks before the o2.
All right I will check it out for vacuum leaks and let u guys know I got a question tho
In the screen shot I posted it is
Eq command that's what the computer wants.... correct?
But wide band eq ratio says 1.03
Dosnt that mean that the wideband is reading 1.03 lambada but the computer wants it to go way richer?
I'm Confused on that part
Thanks for help will let u know
on vac leaks
Its having to command .6 just to get it to 1.03.
Yea don't confuse your PIDs, you are logging the final ACTUAL commanded stoich to get the wideband readings to what you commanded in the tune. You are NOT logging what you commanded in the tune.
So in your case you COMMANDED 1.0 (not logged anywhere), with that calculation you gave it in the tune to achieve 1.0 stoich the end result was something much much leaner, and so it dumped fuel to get the wideband reading closer to your 1.0 commanded. In the log, based on your MAF and injector data, its converting that extra fuel and showing you its pumping the same amount of fuel that in your tune you wrote should have resulted in a 0.6 stoich.
Did you ever figure out what the problem was? What fuel were you running and what was your stoich?
I was looking at this for my own education, dealing with EQ ratio commanded and EQ WB RATIO Bank 1 & Bank 2.. SAE Definition: Commanded EQ Ratio Fuel systems that utilize conventional oxygen sensors shall display the commanded open-loop equivalence ratio while the fuel control system is in open loop. EQ_RAT shall indicate 1.0 while in closed-loop fuel. Fuel systems that utilize widerange/linear oxygen sensors shall display the commanded equivalence ratio in both open-loop and closedloop operation. To obtain the actual A/F ratio being commanded, multiply the stoichiometric A/F ratio by the equivalence ratio. For example, for gasoline, stoichiometric is 14.64:1 ratio. If the fuel control system was commanding a .95 EQ_RAT, the commanded A/F ratio to the engine would be 14.64 x 0.95 = 13.9 A/F ratio.
In this case 14.08:1
so in the log Commanded EQ was 0.6108 or 8.6 AFR and the Bank one 1.03=14.5 and bank 2 1.05=14.7 but i am still confused by the 68% Eq Error.
so actual afr / commanded afr = afr correction factor
8.6/14.08=0.6108 according to this he should be reducing by 39% does the math sound good???
Yeah, I don't agree with the other posts here saying that the commanded EQ being so rich is a result of short term fuel trim correction. That's not how it works.
Commanded EQ does not change depending on fuel trims. the trims act directly on the injector pulse width.
these do command rich and add trims when the maf curve is way off.
just had a 2019 GT, MAF table needed about a 60% (x1.6) increase after an intake install, Commanded was .8 and trims were +20 ST and +40 LT, resulting stoich was of course 1.0
after raising the whole MAF curve 60% commanded was 1.0, actual was 1.0 and trims were 0-2%
Ford uses lambda, GM uses EQ ratio. They are the inverse of each other. Both target 1.0 as stoic. out side of that they mean the opposite. The PIDs should say lambda for Ford vehicles as that's what they are reporting. Your math is correct for lambda.
Calculating EQ% error using lambda values is not going to give you anything that makes sense. You would need to invert the values to get the real EQ ratio. I suspect this is a predefined math being used, meant for GM vehicles.
Actual/ commanded= EQ ratio
14.05/8.6=1.68
((1.68-1.0)/1.0)*100= 68% EQ error.
Originally Posted by murfie
That's not correct.
Air–fuel equivalence ratio is "lambda"
Fuel–air equivalence ratio is "phi"
Ford uses lambda.
Phi is what dodge uses.
So wb eq ratio bank 1 & bank 2 for ford should not be named in this manner. so the math is skewed by naming convention?
Stoich Afr / commanded Afr = Eq Ratio
Example: 14.7 /13.07 = 1.12
example: 14.08 /12.5 = 1.184
1/Lambda = EQ and 1/EQ = Lambda.
1.00= 1.25/1.18 = 1.05
14.08*(1.05)=14.784
an EQ ratio 1 =14.08:1
eq ratio afr ratio
0.78 11.5
0.82 12
0.85 12.5
0.88 13
0.92 13.5
0.95 14
0.99 14.5
1 14.64
1.02 15
1.05 15.5
1.09 16
1.1 16.1
1.12 16.5
1.16 17
1.19 17.5
1.22 18
1.26 18.5
1.29 19
1.3 19.032
1.33 19.5
1.36 20
It's simply divide with EQ ratio where you would multiply with lambda, inverse. Not just invert the ratio.
The names are wrong, but really the problem is the predefined math eq err% that uses those PIDs, shown in the log/screen cap is just meant for GM values that are true EQ ratio and not Fords lambda values.
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