Electronic Control Module (ECM): Acceleration

Fuel enrichment during acceleration is provided by ECM. Sudden opening of throttle valve causes rapid increase in MAP. Pulse width is directly related to MAP, throttle position and coolant temperature. Higher MAP and wider throttle angles give wider pulse width (richer mixture). During enrichment, injector pulses are not in proportion to distributor reference signals (non-synchronized). Any reduction in throttle angle cancels fuel enrichment.