Brice's NA V6 Build

Norrowband primary o2? I think for a 99 truck it is (though 99 4runner I think is wideband...)

I found the o2 scewing with narrowband does not allow leaning out, just enrichment, vs wideband allows both ways (in regards to the FIC).

 

I'm not sure; 2001 truck here.

 

Might have tapped the wrong o2 wire. Check your OBD scanner and see if the o2 values are even changing as you offset the map. Also injector pulse width is the ecu's stock value plus the value in the fuel table or in other words what you are tuning when you alter the fuel table. You might be thinking of injector response time which is an offset value added to the injector pulse width to account for latency in the signal. Mine was set to 486 micro seconds from first load up and hasn't given me any trouble thus far. I have my max voltage clamp set to the highest allowable value, which my maf never reaches.

 

In this post it says I have a wideband, but im not sure if this is a cali truck. And when i replaced the wideband with the bosch counterpart it specified wideband for 1999 I can try putting a resistor in for it and checking the o2 values on my scanner and see what happens.

 

Wide band or not, I don't think you are supposed to tune with the O2 offset. That offset is just to keep the ECU from trimming out your fuel once you tune your fuel injectors. MAF tables shouldn't even be touched IMO.

 

Yeah, so I've read. And without some percentage of the MAF being in use (on the table) the truck wont idle at all it'll just start for half a second then die and maybe the injector pulse width is the culprit, we'll see lol. I can't test anymore till tomorrow though.

 

The o2 sensor has the ultimate word on how much fuel you're spraying in closed loop. It is the only way to tune closed loop. It is somewhat accurate to say you're primarily tuning the pulse width then adjusting the o2 offset to avoid the changes being corrected via short term fuel trims but you have far more control over the closed loop afr with the o2 sensor, the maf value and corresponding load cell and pulse width value are only used initially.

However, it is possible your maf values need adjusting due to the nature of your setup. I highly doubt this is the case but it's not impossible. Keep in mind this is merely a piggy back computer. Every change you make needs to be seen from the trucks ecu. What you see on your computer is completely arbitrary.

I don't recall what my maf settings are now but I do recall if I changed the "mode" setting and nothing else it would change how the truck ran.

 

Mine is set to 50% use below atmospheric any less and and it wont idle, and im blow through. 2.5" to 3" MAF housing then back to 2.5"

 

Yep don't tune via the o2 feedback map, but what your doing is part of the AEM guides as you do want to play with the o2 map at idle to verify its wired right, works, and you can start making a scale-- x% = 14.5, y% = 14.0 etc etc. If your factory wideband, you can put in a voltage translation chart so in the o2 map you do not have to input voltages, but the desired air fuel and the AEM does the rest. I noticed on my setup the OE ECU is CRAZY fast at adapting to o2 signals so you would see if your making a dent very soon, no need to wait around-- in fact mess about too long and that downstream o2 will start calibrating on you. But like StAndrew said, its all for the closed loop boost areas.

Ultimately to get the truck running well in vacuum you should be tuning via the fuel map to compensate for larger injectors, in fact AEM also has a calculator feature to generate the map automatically. That is in the manual, and the above process on o2 scewing tuning is in an AEM made youtube vid.

The only reason to use the MAF map at all IMO is to re-calibrate the MAF voltage for sampling pipe diameter changes from OEM. For crazy use-cases it can be used to simulate a missing MAF (maybe a way to avoid extreme rich conditions when blowing off) but IMO it would come with a drivability penalty IMO. If putting values in the MAF table is allowing your truck to start and run, its telling you to use the fuel map haha- that is where the primary air fuel tuning should be done. The FIC runs injectors way higher than our OE block would require, even on E85- I've been running 625cc for a long time now-- years. I invite any SoCal'ers or at a meet up to see it in action.

 

What size injectors? Your MAF is in a 3" sampling tube?

Your supposed to tune the fuel map so that the fuel trims are 0% at idle, both ST and LT. In fact an initial tuning tool would be a reset relay that pulls ECU power to reset the fuel trims every now and then to help you get dialed in quicker.

If the MAF is in a 3" sampling tube, use the MAF map to calibrate the signal, basically you would be adding a percent to it to make up for the 'unseen' air flow to get your timing and auto shifting OEM mapping back to where it should be. Of course changes to MAF output will require changes to the fuel map to keep fuel trims near 0.

o2 sensor tuning will be in boosted regions, but only really matters in the closed loop boosted regions. In vacuum it can be zero'd out-- keep in mind "zero'd out" is an expression, depending on your sensor type you need a value in all cells, you will need to find the value that gives you stoich in vacuum for the vacuum regions- not because it needs to be that or the truck can't idle correctly, but you can't have zero's in the maps cause in the transitional cells it causes an issue-- a pro type I learned through lots of tuning that is not in the AEM guides.

 

Yeah I need to watch all of AEMs videos relevant to my situation and look into the calculate thing (I read briefly about it)

 

So the o2 map has to have some value in all cells?

 

dependent on o2 sensor type, for wideband I believe I had a value because how the AEM does math, think about it, the value that would be the transition (average) of zero and say 4 volts would/should be 2, but the AEM seems to derp when there is a zero. My memory is foggy here on the o2 mapping, but FOR SURE this applies to the fuel map, you will get a nasty hickup in the cell areas where one cell has a zero, the other a value-- kind of like zero times anything results in zero.

But then the FIC didn't seem to have an issue the EMU has when the OE ECU reaches 100% duty cycle (with the EMU, you must use the MAF clamp before your ECU hits 100% duty cycle or get a nasty miss). Its just funny nuances found in how the systems are doing the calculations behind the scenes.

One step at a time though, get your truck idling at stoich at zero ST and LT fuel trims via fuel map, while also correcting the MAF reading for piping size. Another step after that besides o2 value mapping is reving the engine in neutral to ensure the cam and crank filters are working as they should.

 

Oh yeah, I checked the LTFT and it was -38 lol... I think I need to go in and remove 20% fuel like before, set the MAF table to 0 and clamp it at 5.96 volts (the most it ever sees). Right now I'm removing 55% but I have to put in MAF values for it to run, I believe it is running lean without MAF values but when I put them in it richens up as if it's in open loop. Basically without MAF values I'm running too lean to idle, which makes sense to me since without MAF values and -55% fuel it starts for half a second and the wideband reads like 22-23:1 (too lean to run)

And when it was idling earlier (MAF @ 50% and -55% fuel) I was able to rev to 3000~3500 without hesitation or backfiring, so I believe the 1.8k ohm resistor is doing its job, of course I won't really know until I get it driving under load and more rpms.

Oh and the scan gauge 2's short term fuel trim Xguage code doesn't seem to work... I'll have to try a few others I guess. Also I literally dremeled the MAF housing out of the stock air box lol the inlets are three inches (so it's stock) but it immediately necks down to like 2.5-2.75" on the inner diameter. So it should be seeing airflow as stock, just alot more of it lol

 

Only worry about the MAF tubing diameter directly where the MAF is located.

Is there a crank timing sync?

Can you use your wideband as the source of fuel reading, instead of the oem sensor? As in wire the AFR gauge into the FIC as well?

 

I can (and should) wire the AFR gauge into the AEM but I think that is just for the auxiliary gauge, I don't think it can be used to read the AFRs.

And the AEM taps the crankshaft position sensor. If you're asking can the AEM sync the the timing and crank in the software, then no it cant.

 

Double-check that it cannot use a newer AFR gauge's wideband. I know there other ECUs can.

 

Looks like it can, based off of the SPECS tab. That'd be much easier than fooling around with that old sensor.

 

I recently replaced that sensor with a Bosch one (better design imo) so it's not very old... I'll try seeing if the AEM allows me to tune with the AFR gauge sensor.

 

-38 at idle? And afrs are? If you run the numbers the actual value that should be in the idle load cells is something like -63%. You absolutely need stft to tune so if you can't see them there's really nothing you can do.