Haltech E6X Manual DOS Version - Manual (Page 111)

E6X Manual
111
APPENDIX C INJECTORS
C.1 Injector Impedance
Injectors, when classified electrically, fall into 2 categories:
Saturation Injectors this type of injector derives its name from the method used to
drive it open, the coil is saturated with current to create the
magnetic force used to open the injector until the injector is to
be closed
.
This type of injector has a coil impedance > 12
Ω
,
this means that if 12V is applied across the coil the current will
not exceed 1A.
Peak and Hold this type of injector also derives its name from the method used
to drive the injector open. The coil is saturated with current
until the ECU detects the current has reached a “Peak” value
(4A), at this point the ECU limits the current to a “Hold” value
(1A). The Peak and Hold currents can vary from injector to
injector, the ECU supports 4A Peak - 1A Hold and 8A Peak –
2A Hold per driver. This type of injector has a coil impedance
< 3
Ω
C.2 The Injector Drivers
The ECU uses switched injector drivers that can control the current passing through an
injector by switching the low side of the injector between ground and 12V while the injector
is open. When it is required that the injector be turned off, the low side of the injector is left
floating which will prevent any current from flowing in the coil.
The ECU has 4 separate drivers that are capable of driving either 4A peak - 1A hold or 8A
peak - 2A hold. Each driver can be programmed to drive at either current level by the
programming software. The 8A peak – 2A hold is generally used to drive 2 injectors in
parallel that each require 4A peak – 1A hold drive, this method of connection would be used
with an 8-cylinder engine which used 4A peak – 1A hold injectors.
WARNING:
UNDER NO CIRCUMSTANCES SHOULD YOU MIX SATURATION
AND PEAK-AND-HOLD INJECTORS ON THE ONE DRIVER. THIS
WILL LEAD TO ERRATIC INJECTOR OPERATION.
Should you need to drive more than 8 low impedance injectors or more than 16 high
impedance injectors contact your Haltech dealer.