GEN3 Lean Spikes during WOT in PE

[Boosted Rooster]

I am beating my head against a wall.
I have a 2000 Sierra 1500. I recently swapped in a LS3 converted to 24x/1x. 233/354 cam. LS9 heads and valves, L92 intake and non-return rail. Remote fuel pressure regulator set to 60 psi, no vacuum reference. Holley 76 lb injectors. The OS is 12205612 -> 1273011 SD Enhanced RTT.
I am getting intermittent lean spikes 2-3 seconds into a WOT acceleration while in PE/OL. The injector duty cycle seems to be dropping when this happens.
The spikes happen on the WOT at 6:46 into the log. (a separate issue is it will not shift near the commanded RPM for some reason).
Here is the log, tune and config channels I'm looking at. Please be gentle.

[gametech]

There are tons of things wrong with that tune, but the starting point for fixing it would be proper injector data. You have the IFR and offset data entered as if you were running a referenced return fuel system. Even if everything else was perfect, this would likely cause transient fuel issues. However, I have no idea if any of your injector data is even correct.

[blindsquirrel]

Does Holley have GM-format data for use with non-Holley computers now? Nope. That's like going to Taco Bell and ordering a Big Mac.

[Boosted Rooster]

There are tons of things wrong with that tune, but the starting point for fixing it would be proper injector data. You have the IFR and offset data entered as if you were running a referenced return fuel system. Even if everything else was perfect, this would likely cause transient fuel issues. However, I have no idea if any of your injector data is even correct.

The injector data is stock with the exception of the Flow Rate, Minimum and Default Injector Pulse. That was the only info that came with the injectors. To answer, the injector data is most certainly incorrect.
Forgive me for my ignorance, but would being scaled as a reference return affect WOT acceleration at BARO? Does Injector Data Offest, Minimum and Default Injector Pulse affect injector fuel flow at a constant voltage at a MAP not covered by the table? Does Transient Fuel affect WOT acceleration 2-3 seconds into the event? What affects OL PE/AFR other than the VE and EQ table?

Thank you for any insight

[blindsquirrel]

Well if it goes lean, and injector PW isn't dropping when it goes lean, what else could cause it? Maybe... the amount of fuel being supplied to the injectors?

Do you have a diagnostic-type fuel pressure gauge you can see from the seat while driving?

[Alvin]

The injector data won't cause a issue at WOT.

These two lean spikes at around 7 mins in look like a miss to me. Is there a stumble that goes a long with it? Could be a loose ground or something along those lines too.

[Boosted Rooster]

The injector data won't cause a issue at WOT.

These two lean spikes at around 7 mins in look like a miss to me. Is there a stumble that goes a long with it? Could be a loose ground or something along those lines too.

It sure doesn't feel like a miss, the engine just lays over, hard. I will investigate the grounds though, as I put the grounds at the rear of the engine on the heads instead of the block when I swapped out the LM7 for the LS3.

[blindsquirrel]

Fuel pressure under load. You can only rule that out after you've made it do the lean spike thing while confirming the pressure gauge stayed steady the whole time.

[Boosted Rooster]

Well if it goes lean, and injector PW isn't dropping when it goes lean, what else could cause it? Maybe... the amount of fuel being supplied to the injectors?

Do you have a diagnostic-type fuel pressure gauge you can see from the seat while driving?

Fuel pressure is rock solid at 60 psi. It's a cheapo 15 year old AutoZone gauge, but even if it was off, it should still show a drop. The original 155lph pump was replaced with a 355lph pump last year. I will hook up the vac reference and play with the injector data a little; maybe steal some FIC or Deatschworks data.

[blindsquirrel]

When are you checking the pressure? While it's parked with the hood open, or while driving and while it's doing the lean spike?

[Boosted Rooster]

When the lean spike happens.

[gtstorey]

maybe steal some FIC or Deatschworks data.

It doesn’t work like that. Data is specific to the particular injector.

[Boosted Rooster]

It doesn?t work like that. Data is specific to the particular injector.

I am just going to stick with the stock injector data and work around it. The ignition voltage doesn't vary much. If the fueling is off a few points, so be it.

[blindsquirrel]

If it was possible to just ignore the data and work around it don't you think everyone before you would've just done that? We're trying to help you. If you want to use no-data injectors all you have to do is ditch the stock PCM and go aftermarket.

[Boosted Rooster]

When are you checking the pressure? While it's parked with the hood open, or while driving and while it's doing the lean spike?

I think I have actually figured out my lean spike issue by dumb luck.
My old Autozone fuel pressure gauge started leaking through the gauge itself. I went and borrowed one. Found the fuel pressure was at 85 psi and not 60 like I thought. Turns out letting a $30 fuel pressure gauge sit in your toolbox for 10 years is a bad idea.
Once i set the pressure to 60 psi and put a vacuum reference on the regulator, it seems my fueling issue is corrected.
I guess I may be the blind squirrel today...lol
Thanks for your input.