Wild AFR Oscillations

[slarsen]

Here is the MSQ and zip file of the log.

Bone stock LQ4 6.0 LS (643 cc injectors) with 76 mm turbo and MS3Pro in a 70 Nova.

Fuel pressure 42 psi with vacuum line installed at idle and 18 inches vacuum.

Innovate MTX gauge and controller (pretty close to Tuner Studio numbers).

Early harness so had to change pins 32/33 to get the stepper to respond properly.

DIY boost controller installed but not active.

Cold starts not perfect, hot starts good, idles excellent, drives ok but AFR goes crazy lean and oscillates back and forth like a sine curve.

In the AFR/EGO the ignition events per step was changed from 16 to 32.

Log file was created with autotune on.

Very minor tweak to MSQ in a couple of idle cells only change, otherwise as per log file.

How can I stabilize my AFR? What am I doing wrong?

[Matt Cramer]

The EGO correction is moving too fast. Try doubling or tripling the ignition events per step.