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Discussion Starter #1
I just put a wideband O2 in my car and found it was running way lean. What is your target AFR, idle, cruise and WOT?

I have an adjustable FPR so I turned it up a few cranks at time until I got more favorable AFRs. The car now starts, runs and pulls better than ever. Glad I didn't do any damage running so lean.

The motor set up is stock 302, E7 heads, mystery cam, Edelbrock RPM intake 75mm TB and mass air set for the 24# injectors. Long tubes O/R H and Flowmasters.
 

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You should be in the 12.6-12.9 range under wot if n/a. At idle and cruise you can be around 14.7 or so. Under lower loads you can lean it out a good bit.

Just curious, what we’re you at? Do you actually tune the car?
 

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I just put a wideband O2 in my car and found it was running way lean. What is your target AFR, idle, cruise and WOT?

I have an adjustable FPR so I turned it up a few cranks at time until I got more favorable AFRs. The car now starts, runs and pulls better than ever. Glad I didn't do any damage running so lean.

The motor set up is stock 302, E7 heads, mystery cam, Edelbrock RPM intake 75mm TB and mass air set for the 24# injectors. Long tubes O/R H and Flowmasters.
fueling doesn't work like that, unless you have turned OFF, adaptive fueling

if you still have adaptive fueling on, fueling will trim to where they were told to be in the tune
 

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Discussion Starter #4
It's a stock untouched ECU.
Pegged 19.0 at idle
18s at cruise
13s at wot

Now
18.0 idle
15-16s cruise
12s wot

The fuel pressure is up to 75 psi static.
 

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keep raising it, then when you cant raise it no more
erase the kam, and start over
fun
 

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Discussion Starter #6
I am a total newb to messing with the ecu,
Is there step by step instructions I can follow that you recommend.
And by keep raising it are you referring to the fuel pressure?
 

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What Indy is saying is that the ECU will learn around the higher fuel pressure and then you will have to raise the fuel pressure again, which will make the ECU re-adapt. At some point you will no longer be able to get more fuel pressure and you will have to clear KAM (Keep Alive Memory) where at that point you can lower the fuel pressure back to where you started and then have to make adjustments as the ECU adjusts around what you are doing. It will be a never ending circle. Raise pressure, ECU adapts, clear KAM and start over...repeat. You have to fix the problem that is causing the lean condition to stop the cycle. What you are now doing is a band aid. You are treating the symptom, not the problem.
 

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Discussion Starter #8
Gotcha, what AFRs if everything is working properly is the ECU trying to see?
I can start looking for vacuum leaks and exhaust header leaks but I haven't found anything obvious.

Other random sensors to check?
 

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ECT and ACT sensors.

what mass air are you running?
idle is typical near stoic mid 14 on a sequential fueling system
cruise- again stoic mid 14- mid 15
WOT 12.4-13.2 depends on what the car likes if its NA

cam over lap and WB placement play a large role in what the WB will read at idle. reversion with a decent cam can make the WB read lean or rich.. at idle give the car what it wants and ignore the WB
 

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Discussion Starter #10
The car likes what it is set at right now and the WB readings are closer to what I feel they should be. It wasn't happy when that car was giving me numbers that were way off.
 

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Gotcha, what AFRs if everything is working properly is the ECU trying to see?
I can start looking for vacuum leaks and exhaust header leaks but I haven't found anything obvious.

Other random sensors to check?
In closed loop and at operating temp, the ecm target is 14.64

How does it know what is? It uses 02 sensor feed back

It drives the fuel around 14.64

It purposively cycles the 02s around stoich, 14.64

So the command lambse will be from ~13.5-15.5

It does NOT hold steady, by design

I am going to say that your trickery maf with 24#inj are the problem

If not, we need to verify 02 voltages
 

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Where did you place the wideband O2 sensor?
 

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Discussion Starter #14
Wide band is just after the long tube collector on the passenger side. At the 11 o'clock position.
 

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I wouldn’t be trusting any of that wb data until you can verify with the more accurate stock narrow bands
 

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I wouldn’t be trusting any of that wb data until you can verify with the more accurate stock narrow bands
I like to confirm what my wb says with the nb readings as well. I’ve had a wb sensor fail before, but have yet to have a nb go out.

The trick to dialing In fuel is getting your wideband to match your commanded fuel. Once you have injector slopes close you can do a little fine tuning with the maf curve.
 

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Discussion Starter #17
Here what I know, my car ran like crap. I added a wide band it said my car was running super lean. I increased fuel pressure and my wide band showed the car was running richer and closer to what it should be, and started easier, ran better and felt stronger.

It the wide band dead on? Maybe not but my car is running better so I believe I am on the right track.
 

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Listen to what 96pushrod says.........Lambse=WB......then you should be good

you dont know what lambse is,

so what you are doing is NOT telling the ECM what you want

the ecm is telling YOU what it wants,,,,,,,,,,the ECM will win

this means, if the ECM wants lean it will get it, until it runs to its limits

your method is fine, my first response told you how to do it, its your choice.
 

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First i would pull the codes, they may be there but not light up the check engine light. you could have a failed O2 that is forcing the engine lean.
NB sensors by design are more accurate in a very small range, hence the above advice. you will have to take a voltage reading from the sensor if you have no way of communicating with the ECU or datalogging.
 
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