Stumbling After Cold Start

[dzidaV8]

I have checked the log, you are running a little rich with BLMs around 120, and the moment you tap the throttle it gets momentarily lean from what I can see. Check your fuel pressure and have a look at the spark plugs.
If you still have stock injectors it's a good idea to check them or replace them anyway to D3 type injectors. Stock ones tend to finish their life after those 30 years.

EDIT: I read on other topics that your car is far from stock... I'd say to give it more AE on low temperatures in: "AE Delta TPS Pulse Width Factor Vs. Temp. ".
And work on the tune, log shows rich everywhere.

[90Vette]

Thanks for looking at my logs. I tried checking the fuel pressure before I drove out to VA, but the gauge I got from O'Reilly was leaking like crazy. I don't have time (or tools) to pull a spark plug right now, but the last few times I've had them out they've looked pretty sooty.

I've got new 33.3 lb/hr injectors, so that's not a problem.

Tuning AE was on my to-do list, but man does it look complicated. Here's my current table; about how would you change it?
AE Table.PNG

I have adjusted and updated my VE tables based on several long datalogs, but isn't it normal for it to shift rich and lean as temperature and humidity change?

[dzidaV8]

Right, the fueling can change due to humidity and temp, but I suspect you are hitting a weird transition on the VE table when this stumble occurs. Are your VE tables smooth? Try increasing the TPS AE factor at the temperatures at which the stumble occurs.
"AE Delta TPS Pulse Width Factor Vs. Temp. "

Try using the XDF I attached, I tweaked it some to make it more intuitive, make sure tu use it in category view.

[90Vette]

I've smoothed my VE tables pretty extensively, although there are a few little areas that are a little jagged. Here's the graph of my lower VE table:
VE graph.jpg

Whoops, found the right table. Here it is:
AE Table.PNG
It's stumbling around the 20 °C cell, so I guess increase it there from 1.00 to 1.25 to match the above cells?

Hmm, that's a nice-looking XDF. I like how you added the patches section - maybe I'll finally try patching my BIN if it's that easy. The XDF I'm using (wish I could give credit, but I don't remember who on this forum I got it from) breaks parameters up into sections though, which I've really gotten used to. Check it out. Maybe if I have time I'll make a hybrid of the two.

[sturgillbd]

TPS AE is just a short burst. If it still stumbles, it may need the MAP AE increased also in that area. I booted into windows this eve and replayed your logs. Its a little rich overall but not terrible. Only other thing that stood out was a slow oscillating integrator Do you feel a surge while cruising? I viewed the log using the monitors in Tunerpro and it looks like the integrator is driving the o2 crosscounts. Usually this means you do not have enough proportional gain. Green is O2 voltage, Red is TPS and Blue is the Integrator. If you don't feel a surge, I wouldn't fool with it.

[dzidaV8]

The XDF I'm using (wish I could give credit, but I don't remember who on this forum I got it from) breaks parameters up into sections though, which I've really gotten used to. Check it out. Maybe if I have time I'll make a hybrid of the two.

Right, I removed all the breaks as I prefer category view.

It's stumbling around the 20 °C cell, so I guess increase it there from 1.00 to 1.25 to match the above cells?

Yes, increase that but also adjust the surrounding cells to smooth the table.

[90Vette]

I increased the AE table like so:
Modified AE table.PNG
and hooooly crap that was bad. Whenever I touched the gas, the engine just about died. After about 30s to a minute though, it ran great. Check out the datalog I took, and let me know what you think.
Since adding AE TPS fuel seemed to make it worse for the first little bit, I'm wondering if it's running too rich. The weird thing is, it would have been in a cell with 20% enrichment (20 °C), which doesn't decrease until 56 °C. I don't understand why it would run better so quickly after starting.

TPS AE is just a short burst. If it still stumbles, it may need the MAP AE increased also in that area. I booted into windows this eve and replayed your logs. Its a little rich overall but not terrible. Only other thing that stood out was a slow oscillating integrator Do you feel a surge while cruising? I viewed the log using the monitors in Tunerpro and it looks like the integrator is driving the o2 crosscounts. Usually this means you do not have enough proportional gain. Green is O2 voltage, Red is TPS and Blue is the Integrator. If you don't feel a surge, I wouldn't fool with it.

How exactly does MAP AE work? Somehow I've only ever read about TPS AE.
Also, what are you looking at to determine whether TPS AE needs to be adjusted? I'd looked at O2 volts vs TPS %, but I couldn't find a clear pattern. Do you use the integrator for that?
Interesting about those oscillations. I haven't noticed a surge at cruise, but when I'm coasting in neutral I notice the idle speed oscillates up and down a few hundred RPM. Could that be related? Because that drives me crazy.

Right, I removed all the breaks as I prefer category view.

Yes, increase that but also adjust the surrounding cells to smooth the table.

Oh wow, I didn't even realize category view was a thing. Don't know how I've never played around with that drop-down. That's a lot better, thanks!

[sturgillbd]

Too much AE can cause a stumble too. Too little usually cause a pop back through intake. Too much causes the engine to bog. TPS AE is a short burst as throttle blade opens. MAP AE follows though when the throttle is held open during acceleration. If adding AE makes it worse, you may try to remove 10 % of the TPS AE from your original value at 20C then try 25%. View your log and watch for a TPS increase. If the O2 voltage goes lean, It usually needs more AE. If it goes rich, you need less AE.