It seems like my L28 engine with SU Carbs wants to run away to high RPM at idle. I'm new to tuning, so I might be missing something obvious. The timing gun starts out at high hundreds of RPMs, but grows quickly to above 1200 or 1300 RPM, and I get spooked and cut the ignition. I've been using this as a guide for tuning: https://zcarguide.com/tuning-adjusting-datsun-240z-su-carburetors/ My fast-idle is backed-off, and it looks like the butterfly-valves are mostly closed. B