Check your flipper button optos and interrupters. A worn or chipped interrupter will definitely affect performance. Also check the resistance of your coils. Just because they have 11629 wrappers doesn't mean they aren't 11630's in disguise. I've seen mislabeled coils. Resistance for an 11629 should be right around 4.0 ohms on the high power side. You should also check the voltage at the coils. DC voltage, negative lead on a side rail, then touch each lug with the positive lead. May have to close coin door to see the voltage. You should see ~70 volts there.