AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 21)

Page 21 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
AEM kit P/N 30-2020 (Optional) Bosch Style Injector Connector Kit contains the parts to
assemble 4 injector connectors. The kit contains Four Bosch style female injector connectors
and 10 contacts (2 extra contacts are included for spares).
IMPORTANT!
The contacts are “Pull to Seat” meaning you must feed the wire through the connector housing
BEFORE you crimp on the contacts. The wire is then pulled back into the housing and the
contact locks in place. The contact cannot be inserted or removed from the rear (wire side entry)
of the housing.
Contacts (10 Included)
Plating
Tin Plated
Cable Range 1.00 - 0.05 mm2
Outside Cable Diameter 2.40 - 2.03 mm2
Temperature Range -40 to 125 C
Resistance in mOhms at 20 mV > 10.0 Ohms
Voltage Drop in mV per amp > 3.0 Ohms
Housing (4 Included)
Color
Black
Cavities or Contacts 2
Gender Female
Temperature Range -40 to 125 C
Resistance at 20 mV > 10.0 mOhm
Voltage Drop per amp > 3.0 mV
Exterior Dimensions 27.8L X 29.6W X 20H
Seating Process Pull To Seat
Coils / Electronic Ignition System Basics
An ignition coil is charged when current flows through the primary side of the coil. A coil driver
is required to sink the current and dissipate the heat generated during operation. The coil
outputs from the EMS-4 are used to trigger the drivers. The drivers can either be contained
within the coils themselves or they can be contained within a stand-alone device installed
between the EMS-4 and the coils.
There are several different types of ignition systems in use on modern cars.
They are:

Distributed spark using a single coil and a distributor for all cylinders.

Wasted spark using one coil for two cylinders.

Direct Fire using one coil on plug of each cylinder.
Distributed Spark
Distributed spark systems have been around the longest. As the name implies, the spark is
distributed to the plugs via a coil output to a rotor, then through the distributor cap to the
appropriate plug via a high-tension (HT) lead. This is the most complex system because of the
relationship that has to be maintained between the firing point, rotor to cap terminal angle, and