times by increasing injector pulse width accordingly.
NOTE: Never apply battery voltage directly across a low resistance
injector. This will cause injector damage from solenoid coil
overheating.
Fig. 1: Injector Driver Types - Current and Voltage
CURRENT CONTROLLED CIRCUIT ("PEAK & HOLD")
The current controlled driver inside the computer is more
complex than a voltage controlled driver because as the name implies,
it has to limit current flow in addition to its ON-OFF switching
function. Recall, this driver typically requires injector circuits
with a total leg resistance of less than 12 ohms.
Once the driver is turned ON, it will not limit current flow
until enough time has passed for the injector pintle to open. This
period is preset by the particular manufacturer/system based on the
amount of current flow needed to open their injector. This is
typically between two and six amps. Some manufacturers refer to this
