This tech tip/FAQ reveals a technique to repair a loose distributor HEP pulse ring. A loose pulse ring can contribute to a very poor idle quality, surging on acceleration, reduced gas mileage, and in extreme conditions engine stalling.
The loose pulse ring condition is VERY common on high mileage distributors and is caused by the design that uses melted plastic “rivets” or welds to attach the metal pulse ring to the plastic rotator base. The plastic welds weaken over time and mileage and allows the metal pulse ring to wiggle loosely on the plastic rotator base, This undesired movement causes the engine control unit to constantly vary engine timing and injector pulse event and that is what causes the poor drive ability symptoms.