The ignition timing on my '90 Miata (manual 5-speed) needs to be set w-a-y out of specs (about 18 degrees BTDC instead of 10) for the car to have any pick-up at all. At that setting, the car idles well and drives well, but has a very pronounced hesitation/flat spot when starting from a stand-still and I need to pump the accelerator to increase the RPM before releasing the clutch.

Any ideas out there what might be wrong with it? The sparkplugs are good, and so are the ignition wires.

Thanks! -- Robbi.