Switching back from Auto VE question

[zapp168]

I ran the auto VE per the tutorial on an 02 Camaro. I hit alot of cells and the A/F Gauge looked good, I was satisfied and wanted to switch the tune back to MAF so I reversed the procedure. When I was done the car ran very lean (17's) Anyone know what happened?:nixweiss:

[BillF6531]

Did you tune the MAF?

[hquick]

Yeah...I'd expect you need to tune the MAF.
I'm doing this at present.
Do you have a roadrunner?
If not, just do exactly the same as you did for the auto VE but set B0120 to 400 so your using ONLY the maf for fuelling. Leave trims OFF.
Use map (B5001 MAF calibration table - wideband BEN).
Copy, paste and multiply to B5001.

[mr.prick]

after changing the VE table from stock you
will need to add to the MAF table X% across the board to be safe.
this is where the RR comes in handy.;)

[zapp168]

No I did not tune the MAF, the only other time I used Auto VE was on my car with a turbo so I left it OLSD. I will search MAF tuning and look at the othere information here. Thanks

[zapp168]

Yeah, I think the Road Runner is coming soon......seems like a time saver.

[TAQuickness]

just be sure you have fuel trimming disabled before you attempt to tune the MAF

[zapp168]

[QUOTE=TAQuickness]just be sure you have fuel trimming disabled before you attempt to tune the MAF[/QUOTE

That would be disable b3801 correct?

[hquick]

OK....I have done the same and when I re-enable the trims...after tuning the MAF...I get the same problem...goes very lean?

[zapp168]

Yeah...I'd expect you need to tune the MAF.
I'm doing this at present.
Do you have a roadrunner?
If not, just do exactly the same as you did for the auto VE but set B0120 to 400 so your using ONLY the maf for fuelling. Leave trims OFF.
Use map (B5001 MAF calibration table - wideband BEN).
Copy, paste and multiply to B5001.

Actually I had the car running fine using the MAP, then used the above method to tune the MAF and again the car ran fine, but when I switched back from SD the car ran horrible, at that point I was out of time (and patience) so I left the car in SD. If you don't use the auto VE method, what other methods are there?

[eurospec1]

Actually I had the car running fine using the MAP, then used the above method to tune the MAF and again the car ran fine, but when I switched back from SD the car ran horrible, at that point I was out of time (and patience) so I left the car in SD. If you don't use the auto VE method, what other methods are there?

If you had the car running fine with VE, then tuned the MAF you were already out of speed density, do you mean you tuned the VE, then Did the Maf, all was good then you turned fuel trims on and it went haywire?

Speed density means the Maf is turned off, you cant tune the Maf if you are still in speed density, maybe you tried tuning the maf when you were really still not using it?

[hquick]

I think he means he did the AutoVE in OLSD then switched to OLMAF and tuned the MAF then tried to go CLMAF and that's when it turned to crap...mine too.

[zapp168]

I think he means he did the AutoVE in OLSD then switched to OLMAF and tuned the MAF then tried to go CLMAF and that's when it turned to crap...mine too.

Yes exactly!!

[eurospec1]

My first thought then is your wideband calibrated properly to your EFI LIve unit?

We use LC1's, and we noticed early on that the digital output (logworks) was varrying quite a bit from what EFI Live (the analog out of the wideband) was reporting for actul AFR, if you have this problem it could explain everything. Calibrating the analog input of EFI Live will fix this. (Logworks will be whats accurate if there i a difference in the 2)


Say your wideband is reporting 14.7 to efi live, but what you are actually getting is 12.7 becouse the wideband is not calibrated to the V1 or V2 that you are using.

So your reporting 14.7 in EFI Live, and all is fine and dandy with perfect 1.0 bens on the VE and MAF table, So you turn fuel trims back on. Fuel trim's of course act completely independant of the wideband, and start trimming that 12.7 back to the 14.7 that you are commanding, now EFI Live is going to report 16.7 actual AFR, when in reality the car is running at 14.7.

May very well not be your guy's problem, but fuel trims as im sure you know only adjust the car back to commanded, so if your commanding 14.7 and fuel trims are making your wideband report lean, i would check to see if the information coming out of the wideband into EFI Live is 100% accurate.

[hquick]

Good point. I understand the PLX WBO2's don't need any calibration though?

Thanks

[TAQuickness]

you would still need to calibrate V2's AI's to accept an accurate reading from your WB

[joecar]

Check if your wideband is reporting the correct AFR to FlashScan V2:

run in closed loop (or semi open/closed loop), you should see the AFR cycle tightly around stoich AFR.

[hquick]

I'm using a V1.

[eurospec1]

I'm using a V1.

Still have to call the V1, its a bit of a lengthier process using a bit of Math and re-writing some code, but its doable :)

[FreddyG]

Still have to call the V1, its a bit of a lengthier process using a bit of Math and re-writing some code, but its doable :)

Do you have any links available that would show us how to do it? :cheers:

Thanks in advance!

[hquick]

Yeah...some info on the process would be much appreciated.
Today I went out and tried to tune the Maf again.
I got everything at 99-1.01 BEN.
After doing it...I would accelerate and then back off and the AFR guage would show extremely lean...as high as 19+
I have no idea why it's doing this,

[eurospec1]

Yeah...some info on the process would be much appreciated.
Today I went out and tried to tune the Maf again.
I got everything at 99-1.01 BEN.
After doing it...I would accelerate and then back off and the AFR guage would show extremely lean...as high as 19+
I have no idea why it's doing this,

Unfortunetaly, i have only owned V2's, so i am not familiar with the V1 Input cal procedure, otherwise i would be more then happy to share it with you. I do Know that it can and should be done, hopefully someone can post here the procedure for the V1