Injection Pulse Width - Mathematical Description

As mentioned earlier, the basic injection pulse occurs at idle when the engine is warm, and the pulse width is changed by the computer to provide more fuel as the engine's requirements increase with speed and load.

The computer modulates the basic pulse width by a multiplier that is composed of the inputs of:
^ the air flow sensor
^ the air temperature sensor
^ the coolant temperature sensor
^ the oxygen sensor
^ the manifold pressure sensor
^ the throttle position sensor for acceleration
^ the throttle position sensor for deceleration

Stated in mathematical terms, the relationship is:
T = T(B) x K, where K = K(wt) x K(af) x K(at) x K(as) x K(fb) x K(ap) x K(aci) x K(dci)


T = working injection pulse width
T(b) = Basic injection pulse width
K(wt) = Coolant temperature sensor factor
K(af) = Factor for air flow sensor or engine speed
K(at) = Intake air temperature sensor factor
K(as) = Timer circuit and coolant temp. sensor factor
K(fb) = Oxygen sensor factor
K(ap) = Pressure sensor factor
K(aci) a= Factor for throttle position sensor - accelerating K(dci) = Factor for throttle position sensor - decelerating