Problem with tune - Hanging Idle and periodic lean spikes

[07RCSB]

Hi, I have a 2007 Silverado (Classic) 1500. Can you take a look at the tune file?

The engine starts and runs great. Whenever I rev or come up to a stop sign the idle periodically hangs at 1200. Also while driving the engine periodically looses all power and when I look at my wideband it shows a lean spike (18 or so). Then it bounces right back and drives perfect again. Under full throttle there seems to be no issues..

2003 LQ4, DBW, off-road y-pipe
Trickflow 228/230 .585/.585 112
PCM is a 2007 Serv No 12602801
All else is factory
5 speed manual NV3500

My tuner will not acknowledge my issues.

This was originally a 4.3 V6 by the way

[ryan_axberg]

I bet when you say it looses all power it is entering DFCO. It just cuts fuel when you don't need it. You can disable it if you go under the fuel tab, then go, cutoff,dfco. Where it says deceleration fuel cutoff enable ECT change that to 250 then it won't enable. It is also quite a bit of timing to be running in my opinion.

[07RCSB]

Thank you for the quick reply Ryan. I will make the change you suggested and also lower high octane spark maybe by 5 percent.

The cutout usually happens when slowly accelerating. I can duplicate it over and over by shifting and accelerating slowly. It always spikes to lean at around 1600-1800 and cuts out. When I lug it. If you wind it out all things are normal. I recorded it with my wideband in the PID list.

The idle hang is super annoying. This motor was a return style fuel system originally. I changed the rail to a returnless and then changed the injector tables to match a returnless LQ4 from the repository. They are the stock 25lb injectors. Occasionally a P0507 code appears for the IAC. But of course this has no IAC. So I cleaned the TB and checked for any vacuum leaks.

[ryan_axberg]

if you look at your long term fuel trims and your stft you can see that it is adding in a bit of fuel in the 1600-1800 rpm range. You could set up a commanded afr vs actual afr chart and use that to check your fueling by using your o2 sensors in closed loop or your wideband in open loop and reset fuel trims. If you log stit, ltit, and throttle follower airflow you should be able to see what is causing your hanging idle.

[07RCSB]

Good afternoon Ryan. Could you please take an additional look at the new data I am providing. I set up the scanner a lot better to include all of the PIDs you asked for. And I disabled DFCO. I am uploading my new tune, 2 example scans. 1 with the lean spike and 1 with the idle hang. And my Channel and Chart configs.