Surging problems footbraking and light/no throttle cruise/coast

Most obvious is idling fine, just crack throttle and car goes into heavy surge. Tried making timing in the 1200-1800 rpm area all the same, and that help the size of the wave, but still surges

Attached log file if you check the comments section I labled some of the surging instances with an S. I think the last one the timing was a dead steady 31 degees and pedal input staying steady but still surges (not nearly as pronounced but obviously the spark ramping up was a contributor to the swing size, but not the cause

footbrakesurge log is an earlier one before I messed with the timing

Base running airflow I had put a good bit in but too much and then timing is working to

Your O2 problem once fixed will help this a whole lot if not fix it all together. After that I highly recommend lowering your min airflow, especially if your running SD only. Haven't checked the tune to see if you are or not, but if your are your min air table needs to be very low - Too high and the engine will add fuel, then pull fuel to try and hit the airflow numbers resulting in a cruise surge especially with light throttle inputs.

To address timing, pull around 10 degrees out of your whole idle advance table, then turn around and add back around 4 to 6 degrees in your idle areas in the main timing table.

Wondering if your injector data is correct? What's air fuel doing while the surging is taking place? Is the surging still following your O2's? Just sounding like fueling is really unstable....

stock inj and data far as I know, I inherited this problem.

I have 13 deg in idle timing table, and @30 and up in that are in main table. 13 is usually low enough to allow it to feed plenty of timing into it (some people put alot into it and it doesnt have any head room to add and "catch" the idle) What are you aiming for there?

What computer is in that thing? The logging rate is ridiculous compared to what I get. You got more data in 6 minutes than I get in 30, lol.

Shooting for around 6 to 7 degrees max timing in idle areas of your idle advance table then around 4 to 6 more degrees timing or at least almost identical timing to your 1200 and up areas in your main timing table. After that we can adjust your idle airflow tables to stabilize it if the o2's and timing don't fix it.

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Originally Posted by schpenxel

What computer is in that thing? The logging rate is ridiculous compared to what I get. You got more data in 6 minutes than I get in 30, lol.

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The newer stufff is like that, this is 07 Silverado ECU

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Originally Posted by GrannySShifting

The newer stufff is like that, this is 07 Silverado ECU

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Yeah I've got an '07 Escalade so probably same or similar computer. The logging rate is quite awesome. Wish my Corvette had something newer.. ah well.

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Originally Posted by GHuggins

Shooting for around 6 to 7 degrees max timing in idle areas of your idle advance table then around 4 to 6 more degrees timing or at least almost identical timing to your 1200 and up areas in your main timing table. After that we can adjust your idle airflow tables to stabilize it if the o2's and timing don't fix it.

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Tried that. Absolutely horrendous surging even sitting still in park with that