I am not an experienced tuner by any means but have been doing a lot of research to sniff out this bug and I have found what i believe to be the proper fix for this issue. Experienced tuners please correct me where I am wrong and please chime in. I have seen a lot of others while researching this and the usual fix I have seen is "just leave CL off and dont look back." While I was close to doing this, here is what I found after watching... over and over again.... at .1x speed sections of my logs with OLSD and CLSD. Apologies in advance if this is hard to follow.

Setup:

2000 camaro ss
stock pcm and hp tuners SD 1bar custom OS
44lb Lucas injectors - the main reason for closed loop issues even with good data


I have OLSD Wideband tuned my VE to the T and OLSD operation is smooth averaging stoich in all cells. My WB and stock NB readings are in line so all is good there. Again when switching to closed loop I had severe negative decel trims with lean throttle transients due to trim carryover. With some driving this smoothed out some while STFT filled its table.

My Stock Injector Pulse tables
Short Pulse Limit ? 3.997
Adder ? stock
Min Injector Pulse ? 1.277
Default ? 1.277
Transient min mg - .041

Adjustments I made with 44lb injector install before VE tuning
1- Changed short pulse limit to 1.277
2- Zeroed out short pulse adder down to the 1.277 limit
Logs during Wideband tuning in OL: showed injectors were operating properly and running down to values around 1.4-1.5. VE table was good and OL operation was smooth with stoich decel, cruise, and PE map looked good. Again injectors were operating correctly in OL and pulse widths were moving and above the minimum of 1.277

Logs when switching to CLSD with STFT enable and LTFTs turned off in vcm scanner: Under decel afr was rich and inj pulse widths were bottoming out around 1.8 as STFTs in both banks creeped up to 16-20 before FREEZING. This is the cause of the Lean Tip in everyone experiences with larger injectors. My first thoughts were Closed loop has something to do with dynamic airflow Zones but after watching 10 different occurances of this in my log it was not MAP related. It appears that the closed loop fueling uses Injector Pulse width corrections to adjust AFR. NO KIDDING!!ha So why were injectors operating normally in OL but bottoming out at 1.8 in closed loop????

My attempts to fix as follows
1. Min fuel mg changed to .002 to see if pulse widths change: No change, trims go hard negative under decel and STFTS creep hard negative before they FREEZE and carry back into throttle.
2. Leaving min fuel mg at .002 I cut the Min and Default injector pulse limits in Half:

Now my STFTs are operating and not freezing under decel and my AFR looks good with injector PWs down in the 1.4-1.5 range. While they are still slightly negative, they don?t transition hard and cause lean tip in.

How do inj pulse width limits translate to STFTS in the stock pcm and HP tuners? Why are the Min and Default inj pulse limits only active in Closed Loop operation with no affect in open loop?

Anyway here was my fix for this issue. For some reason in closed loop 1.277 for min inj pulse width translates into 1.8ms in closed loop operation? Instead of messing with your VE, make sure your injector PW in closed loop aren?t bottoming out and freezing STFTS negative. IF AFTER you reduce the Min and Default PWs you are lean on decel but your PWs are operating normally?. Your VE is off. Can someone experienced explain how and why these limits work in closed loop?