commanded aft is staying at 14.68 while trying to tune WOT

[ThirdCoastTBSS]

been fighting with this truck for a while. 2005 5.3 heads cam. finally got to the WOT tuning portion and the scanner table display "commanded afr res" will not reflect my editor EQ table. is it staying in closed loop? it says 14.68 the entire run.
appreciate any input. I attached the most current files from each. thanks again in advance.

[fullthrottle]

Where is your wideband? It definitely seems that the car is not going into open loop. dude!!! VE table looks like smashed ass!! (im going to assume its from trying to compensate for your vehicles lack of going into PE) If it's you tuning it please stop and consult a pro and or do a lot more learning before trying to tune yourself. sorry for being a dick but you are going to wreck your stuff bro.


try setting the PE delay to 0

[mowton]

OK, back away from the keyboard and lets talk....You do have some major issues with the tune as well as the setup it appears. Your PE is set to 55 kPa and 90% throttle but your log shows you never go above 84% so you wont trigger PE. Need to relook at your Throttle plate settings and make sure they can go to full open which is app 88%. Change your PE settings to 85kPa and throttle to like 15-20%, that way the load is requesting the added fueling.

Agree above, VE and MAF look a bit hosed, I would go back to stock and start all over. Please make sure you find a tutorial on MAF and VE tuning. There are many that can found by searching on this and other forums. This tune looks like it wants to be a Speed density ( p0101-0103 fial on first err, but MAF High fail is still like 16500, s/b 0 if you are going for VE tuning. Or P0101-103 should be fail on 2nd error if going for MAF only. Also High RPM Disable should be 400 for MAF as well and like 8000 for Speed Density. You will find all of this in the tutorials.

Also you can not tune WOT with a wideband as iterated above!!!!!!

Below is a tuning tutorial attached for your review. There are many more...do some research first before you begin the tuning process. Ask questions and get the process down to an understanding.

Ed M

VE and MAF Tuning 101.doc

[nkautz]

You're on the right track. I see your wideband. You need to set your PE to come on sooner. I like Map enable 15kpa. Throttle enable hot and cold at 35%. Delay RPM 1000. Delay 0.0sec. If you're naturally aspirated set your PE ratio at 1.2 across the board, which will give you 12.2 AFR on gas. You can lean it out from there probably ending up around 12.5-12.7. Watch for knock retard always. Your wot spark advance is low , which is probably why you didn't knock on your lean pull. You want your VE to be as smooth as possible, no spikes. Same with MAF. Ease into WOT tuning and make sure everything is doing what it's supposed to do.

[mowton]

You're on the right track. I see your wideband. You need to set your PE to come on sooner. I like Map enable 15kpa. Throttle enable hot and cold at 35%. Delay RPM 1000. Delay 0.0sec. If you're naturally aspirated set your PE ratio at 1.2 across the board, which will give you 12.2 AFR on gas. You can lean it out from there probably ending up around 12.5-12.7. Watch for knock retard always. Your wot spark advance is low , which is probably why you didn't knock on your lean pull. You want your VE to be as smooth as possible, no spikes. Same with MAF. Ease into WOT tuning and make sure everything is doing what it's supposed to do.

????? right track? The tune could have blown his motor.....PE would never come on as his TP% only hits 80-85% and the tune is set for 90%....VE wrong because his tuning approach for MAF and SD were in error.... Gave him a tutorial to straighten him out and get him on the right track.

Ed M

Ed M

[ThirdCoastTBSS]

Thanks for all the coments and all criticism is welcome, as i just want to get this tuned properly and safe. We did start over completly with a factory tune. Mowton, "One" issue we were having was the manual we were following to do our VE tuning stated to change P0103, but never stated to turn it back and therefore caused us to continue from there in SD. i have a better understanding of the process now. thanks for the attach doc. it made things a lot clearer. although i do have one question, it states before starting the VE using stfts to make sure your ltfts are close. does this mean i should use histogram 3 on the scanner "ltft" and perform the copy/paste to primary table until my ltfts are close and then follow the guide you provided and disable the ltft and perform stft VE tuning etc. also the vehicle surges a little when you are just idling around in gear kinda driving it self until you bump the throttle, if that makes sense.
i know this has something to do with my idle settings. any thoughts. thanks again everyone i appreciate the help. i will upload our new tune prior to WOT tonight.

[mowton]

Thanks for all the coments and all criticism is welcome, as i just want to get this tuned properly and safe. We did start over completly with a factory tune. Mowton, "One" issue we were having was the manual we were following to do our VE tuning stated to change P0103, but never stated to turn it back and therefore caused us to continue from there in SD. i have a better understanding of the process now. thanks for the attach doc. it made things a lot clearer. although i do have one question, it states before starting the VE using stfts to make sure your ltfts are close. does this mean i should use histogram 3 on the scanner "ltft" and perform the copy/paste to primary table until my ltfts are close and then follow the guide you provided and disable the ltft and perform stft VE tuning etc. also the vehicle surges a little when you are just idling around in gear kinda driving it self until you bump the throttle, if that makes sense.
i know this has something to do with my idle settings. any thoughts. thanks again everyone i appreciate the help. i will upload our new tune prior to WOT tonight.

Yes, you can utilize the LTFT and they will slowly migrate to zero as you get closer and closer to 0% error with your corrections. The thing to watch for in tuning with the LTFT is nice easy accelerator movements and long steady state driving to get them as accurate as possible. Once the LTFT are say within 4-5%, you can disable them and just go with the STFT. One very important step though is to reset your fuel trims prior to the start of your next logging session after a tune update. This is done through the VCM. I hit the fuel trim reset button several times just to make sure :-)

The off idle surging could be timing, RAF etc and you can address that after you get the MAF and VE tuned.

Have you installed a WB yet, if not, please stay out of WOT/PE testing fro now.

Last question, have you looked to see why your TPS only goes to 85%?

Also, sorry if I came across a bit harsh, was just I didnt feel at the time the comment was right and knew we had provided the direction to get you going in the right direction.

Let me know if you need anything else.

Ed M

[nkautz]

By right track I meant that he's not that far off from tackling wot tuning , he's got the wideband , he's got timing turned down , he noticed the fueling issue.... but yes , I personally would not wot tune my car if I were him without doing plenty more learning. It just seemed like he was getting a bit of a hard time from the comments and I remember being in his position not long ago.

[ThirdCoastTBSS]

ok so as promised here are the recent files. I did go back and start with ltfts and continue to the guide you sent me mowton, thanks again. truck is 100% better. The scan file is of our WOT as we creep closer to our target afr. few questions,

the fuel inj duty cycle only gets to 77 percent and then drops off around 4200 rpms. is there something limiting it from continuing to produce, or am I missing a table here?

After the WOT AFR is correct should I start adjusting the spark and fuel at this point to get my cyl vol as high as possible with no knock?

There is still a slight hesitation under hard acceleration under low rpms i.e. 1300rpm-WOT

mowton, your question about my limited tps%, is that it is bad lol. It shows 9-13% without touching accelerator.

Thank you again for everyone's input, I hope to one day be able to share my knowledge with others the way you are now with us.

[nkautz]

Woah. Still no good. Your engine coolant temp is 240*, that's overheating. You went way lean for the 2nd half of your pull when it switched over to MAF because your MAF is not tuned. You gotta read a tuning guide on how to tune MAF. The throttle position problem is definitely worth looking into. I would want everything working right if it was my engine, especially before I stomp on the throttle.

[mowton]

ok so as promised here are the recent files. I did go back and start with ltfts and continue to the guide you sent me mowton, thanks again. truck is 100% better. The scan file is of our WOT as we creep closer to our target afr. few questions,

the fuel inj duty cycle only gets to 77 percent and then drops off around 4200 rpms. is there something limiting it from continuing to produce, or am I missing a table here?

After the WOT AFR is correct should I start adjusting the spark and fuel at this point to get my cyl vol as high as possible with no knock?

There is still a slight hesitation under hard acceleration under low rpms i.e. 1300rpm-WOT

mowton, your question about my limited tps%, is that it is bad lol. It shows 9-13% without touching accelerator.

Thank you again for everyone's input, I hope to one day be able to share my knowledge with others the way you are now with us.

I agree with the temps....gotta get that straightened out as well as the TPS%. Looks like this may have been a restart after heatsoak.

Is this a Drive by wire (DBW) or a Drive by cable (DBC)? DBW has no Idle Air Control (IAC) and will show idle percentages in the 5-15% range depending on setup because it actually manipulates the throttle blade to control idle airflow while a DBC will have the throttle blade closed (0%) and use the IAC to open and close to control Idle airflow.

The tune you posted is back in what is configured known as MAF/VE Blended mode with LTFT disabled. Means that at 4000 rpm (High RPM Disable), the pcm will use the MAF for fueling but will validate with the VE values for periods of transients and when the two don't agree by a certain amount, use the VE as a fail over value. After 4000 rpm (more like steady state) the PCM uses the MAF values. We assume you were in open loop and in Speed Density (DTC P0101-0103 fails 1st err, MAF High fail = 0 etc).

Now that you have a wideband installed, you could tune with it in open loop, but we will leave that for another day.

Also, I noticed in the writeup I posted that it says to set a histogram filter to 14.6 afr, delete that filter please. That is a carry over from another procedure that I don't really agree with. Data collected while in PE mode is as useful as when not. The goal again is to keep your pedal movements steady and slow to preclude large transients which will effect the accuracy of the data. You can change gears and find hills to help populate cells you normally wouldn't hit during normal driving. Remember ---- squeeze gently, much like firing a gun....which many times you wish you had :-) Tune the VE to 4000 rpm and then just take the tuning change trend at 4000 update balance of VE that global percentage..

Please post the tune file that was loaded during the posted log.

Lastly you need to delete some PIDs in you scan, way too many. Limit it to no more that 22-24. You are showing 45. Take the idle stuff and generate a separate .cfg with other required PIDs like temp, timing etc. You wont tune idle and MAF/VEat the same time anyways. If you have LTFT disabled then you can eliminate them.

Thanks,

Ed M