Distributor curving.

Which distributor? MP?

Check the air gap on reluctor/pickup.

Check all the wiring, firing order, the normal stuff. Look over the rotor, make sure center tang isn't cracked/broken. Cap got any cracks.

If the only thing you did was remove and mess with the distributor, I'd guess the issue is isolated there.

Is the accelerator pump adjusted properly and providing enough squirt when it's needed?