I've read many of your posts on this forum. Pot meet kettle.

 

Agreeing you are smug though. And maybe you have me confused with CoSpeed....we arent the same person. No one is really giving evidence to the contrary besides pointing at me and thumbing your nose.
No one can agree to disagree theyd rather be 100% right no matter what. Well, nothing is perfect.
Op stay on your path. fix the issue and tune it however you wish.

 

Summary: LS6, FAST 102, FAST fuel rails, LS2 TB, TrickFlow 220 heads, a Comp Cam 229/239 .627"/.621" 111.5+3, Kooks long tubes with high flow cats, Deka 60lb injectors, a Walboro 255 pump w/ 3/8 line from the pump to rails and -6AN return through an ext fuel pressure regulator set at 58psi on the back side of the rails. (in tank FPR removed)

Here's the first HPL/HPT file set... with a basic dyno tune applied but still exhibiting intermittent idle bounce when coming off the throttle (particularly at low speeds).

 

Then I added 4 to my VE table, forced open loop, reset fuel trims and set them to learn. That's "test1". I don't know if it matters but I only went around the block once w/ these and didn't get above like 30mph.

 

First off thats one tight cam. prob makes quite a bit of dcr. second the injectors are a tad on the large size. just from reading not even looking at the files.

 

Finally, I kept closed loop forced on, kept fuel trims on learn and reduced some of my injector settings like min inj pulse, default inj pulse, short pulse limit & min fuel milligrams. That's test2.

 

yeah, the injectors seldom see over like 15%. I'm thinking of putting the stockers back in or some in the 36-48lb range

 

42Lb injectors will be fine for your setup. The idle quality may improve as well as other aspects.

 

Return my $350.00 please. I bit hook line & sinker.

 

Here are a few quotes for starters and don't ask for a response because I'm not going to bother.

Nope.

Nope.

Nope.

One can say that if your STFTs can't take care of your minor fueling changes on a daily basis and you need LTFTs to pickup the slack then you aren't close enough in your fueling adjustments. Plenty of ways to skin a cat but let's not pretend that they are necessary when your fueling should need close to zero correction to begin with if it's tuned accurately.

 

Acknowledged that you can tune without LTFTs. My thing is, if I have 0s for LTFTs all the time - even when I set it up to go lean - why do I get STFT but no LTFT readings? Is it an indication of something wrong with my o2s or some setting in my tune? Am I getting STFTs because I have STFT Open Loop enabled and I'm not able to even force Closed Loop and with fuel trims on?

btw, no exhaust or vacuum leaks that I can find and the o2 wiring appears to be good. no DTCs related to the front o2s either

 

I have not seen an instance where it effects the ltfts.

 

Well they have on any vehicle I have reset the trims on...maybe it is not exactly 50 miles but it takes some run time before they start locking in. No need to for the attitude btw...we are all here having a adult conversation.

 

Looking at the log file you posted it sure appears it's in full closed loop operation and it's even changing fuel trim cells as you are driving. It's especially interesting in that they still don't change when you manually force it into closed loop and turn on the trims with the bidirectional controls in the scanner.

I'm going to have to guess that somehow the LTFTs in the scanner aren't mapped correctly or something weird happened when it originally scanned the car. Maybe try going into your Documents\HP Tuners\VCM Scanner\Vehicles\ folder and delete the 12592618.os file so that when you re-open the scanner it will re-scan the vehicle.

 

I'll give it a try but not hopeful since it didn't read LTFTs on another person's computer either.

 

Yeah that doesn't sound good either. Maybe also make sure you have the latest version of HPT before reconnecting and rescanning as well.

If none of that works I would just turn off the LTFTs with the master switch and make sure you click on the clear fuel trims button in the scanner afterwards several times and just use the STFTs at that point so they aren't an issue.

 

Yes. My guess is there is still a condition not being met to enable closed loop. You need to log the fuel system status bits to be see if closed loop ever engages.

 

Something like this:

1. set PE to 1.0 up till 1200RPM
2. set TPS enable PE to 0 up till 1200RPM
3. set open loop F/A to 1.0 up till idle MAP, so if idle at 60kPa, 0-60kPa from say, 20*C up
4. disable LTFTs (it sucks... a lot) (not necessary for this, but LTFT truly do suck)
5. set PE MAP enable to 15kpa
6. set PE enable delay RPM to 0
7. disable the P0131 and P0151 DTC codes
8. disable STFT open loop enable (if its not already)

Works for me.

 

thanks to coSPEED2, this problem is solved.

It was so strange having STFTs, no O2 codes and all wires from the O2s to the PCM testing fine that coSPEED2 suggested I take the car to a GM dealer and have them re-flash the computer back to the latest OS. That was it. I've got LTFTs again and can start tuning in earnest.

coSPEED2 has been beyond great in helping me with this issue and tuning in general. I'll buy my parts through them from now on...

 

Thanks alot for the comments. We try to go above and beyond on every project but can be stretched pretty thin sometimes. Thank you for the appreciation!