lq4 swapped lean help

[cmcmanus2]

I swapped a 03 lq4 into my 99 silverado, the truck had a 5.3 from factory. I'm using a 4110 aem wideband gauge. I'm relatively new to tuning so I have been watching videos on youtube from goat rope garage. I set up my AFR histogram to tune my MAF tuning like he shows for gen 3. I have been through the video and redone it several times, so I'm positive I have done that right. When my MAF and my LTFT are on the truck idles at AFR 14.7-15, now when I shut the MAF AND LTFT off the AFR start at 16.o and climb to 18. In the video it shows multiplying MAF 1.15. I multiplied MAF table by 1.80 and flashed the ECM. I started the truck and the AFR do the exact same thing, they start at 16 and go to 18. I have went into the VE tables and multiplied them several times, every time with the same results AFR 16 THEN CLIMBS TO 18. Any ideas?

[5FDP]

So clearly you are doing something wrong when it comes to tuning the MAF/VE with the wideband. Likely leaving something on when using the AFR error.

Closed loop and fuel trims must be disabled completely along with the trims reset prior to data logging. If MAF tuning you need to change the dynamic airflow high rpm disable setting to a much lower number and a much higher number when VE tuning with the MAF sensor failed.

Cat over temp must be disable too and if you still have the stock 1999 computers operating system, all VE changes are done to the secondary VE table. The data in the secondary VE need to be matched to the primary VE table as well, the secondary VE just has less resolution but both tables need to be the same.

Did you swap injectors when you installed that 6.0??

I ask because the factory 5.3 injectors in a 1999 truck are too small for a 6.0.



And always post the tune and logs, we can't help you without those.

[cmcmanus2]

Ok so it turns out that I did not clear the LTFT and I didn't have my secondary VE matching my primary. So thanks for the advice. I multiplied my MAF table and my primary and secondary VE tables by 1.80. So now my problem is AEM wide band 4110 is outputting 1.0-1.02 to my computer, while the actual gauge is reading AFR of 10.0. I have the gauge set up of user defined AEM 4110 divided by 10. My last problem is my histograms are not polling data, I have exited out of scanner. I have reset my computer, I have even deleted and installed beta. when I try to repoll data the its not clickable. My gauge is set to p0

I used the 6.0 injectors.

What is the best way to post my tune and logs?

[5FDP]

There should be zero reason to add 80% worth of fuel to any table on just a 6.0. You should only have to copy over stock 6.0 MAF/VE and injector data to get it running. If all that is right and fuel pressure is correct it should start and run like normal.

I can't help with the wideband part not working. For one make sure the wideband and computer settings are both set the same for the read out. If the gauge is set to AFR the channel in the scanner needs to have the units as AFR and not Lambda. Right click the channel to change units.


Click the "Go Advanced" box at the bottom of the reply box and there will be an attachment paperclip icon you can click.

[cmcmanus2]

I used a 6.0 VE table. As far as adding 80 percent of fuel, I was following the the example set from goat rope garage. The readout on my computer showed that the truck was running 1.80 lean. I used lambda because it made the math easier.

[5FDP]

But think about it for a minute. Why would just an engine swap require 80% worth of fuel when the engine is not 80% larger. I know that math doesn't add up exactly on those two values but in the big picture here there is no reason that it would ever require that much more fuel just to run. When looking at a 5.3 VE table and a 6.0 VE table they are not that different. The 6.0 needs more fuel but it's not 80% worth.


If your fuel trims and the wideband are through the roof lean you have a bigger issue at hand. Be it low fuel pressure, vacuum leak or exhaust leaks pre o2 and wideband.

[cmcmanus2]

IDK man nothing was working, then lambda wanted 1.8. which satisfied the computer, but the gauge made it run pig rich. Hp tuners isn't working right, so I'm pretty frustrated right at the moment!

[5FDP]

I'm still in the dark without a tune and log file.

If anything just flash it back to stock and only change the injector data, it should run normally on a 5.3 tune. If it can't even do that then it's not a tuning problem, it's a mechanical issue.