Equus 3120 - OBD 2&1 Tool Kit - Manual (Page 59)

OBD2 & 1 57
E
Ford OBD1 Systems
ADDITIONAL TESTS FOR EEC-IV SYSTEMS - CYLINDER BALANCE TEST
SEFI Introduction
Sequential Electronic Fuel Injection (SEFI) belongs to a family of fuel
injection systems called "Multi-port/Multipoint Fuel Injection". Multi-
port (MFI) fuel injection systems contain one fuel injector per cylinder,
and the vehicle's computer electronically controls their operation. On
some multi-port fuel injection systems, the injectors all fire at the same
time and at every engine revolution. On other systems the injectors fire
in groups and/or at every other engine revolution. What distinguishes
Sequential Electronic Fuel Injection systems from other multi-port fuel
injection systems is that each injector is independently energized and
fires sequentially one after the other in the proper firing order. This
gives the vehicle's computer more control to cut the fuel to one injec-
tor at a time (this can't be accomplished on the other systems because
they fire in groups of two ore more injectors).
Cylinder Balance Test Procedure
Check your vehicle thoroughly before performing any test.
See Before You Begin on page 17 for details.
ALWAYS observe safety precautions whenever working on a
vehicle. Read and follow Safety Precautions on page 3 before
performing this test.
1. Locate the vehicle's Data Link Connector (DLC). See Data Link
Connector (DLC) on page 46 for connector location.
Some DLCs have a plastic cover that must be removed
before connecting the Tool cable connector.
2. Connect the Tool cable (with the Ford
Connector Cable Adaptor attached) to
the Tool, then connect the adaptor to the
vehicle's DLC. Press the POWER/LINK
button to turn the Tool ON, then
press the ENTER/FF button to con-
tinue.
■ The Ford EEC-IV System menu dis-
plays.
3. From the Ford EEC-IV System menu,
highlight Cylinder Balance Test, then
press the ENTER/FF
button.
4. Start and warm-up engine to normal
operating temperature. Press the
ENTER/FF button to continue.
5. Turn ignition key OFF and wait for the on screen prompt. If you wish
to exit the Cylinder Balance test at this time, press the ENTER/FF
button.