I think you need to do the timing and IQ at the same time to match them properly.
Bump the timing up to the line after adjusting the IQ which is insanely low, which means over fueling.
I'm going to guess that your timing is causing the issue and the IQ is compensating.
Basically the surge is the ECM fueling to keep it running as the timing is to far down on the graph.
In my experience the IQ changes when I set the timing. I would set the computer default, 32765 if I remember correctly, and then set the timing to where it should be. Finally I would hammer mod it to the right IQ of 3 and then drive and adjust the IQ ONLY to the best setting.
You're fighting one aspect with the other and adjustment to one throws off the other, they're not in balance and it of spec together causing surge.