Mercury MerCruiser MCM 454 Mag MPI Service Manual page 679

GENERAL SYSTEM DIAGNOSTICS
Chart A-7 (3 of 6): Ignition System Check (Continued)
Step
1
2
3
Index
Page 5E-86
Downloaded from https://needmanual.com/
Action
Was the "On-Board Diagnostic"
(OBD) System
Performed?
1. Check spark plug wires for
open circuits, cracks
insulation, or improper seat-
ing of terminals at spark
plugs, distributor cap, and
coil tower before proceeding
with this table.
2. Disconnect 5-wire harness
connector (WHITE and PINK
wires).
3. Install a temporary jumper
wire between the 2 PINK
wires at the connector of the
boat harness. This is CkT 3
for the ignition circuit.
4. Check tor secondary spark. If
there is "no spark" at one
wire, check a few more wires.
A few sparks and then noth-
ing is considered "no spark."
Is Adequate Spark Present At
All Cylinders?
Remove distributor cap and
verify rotation of distributor rotor.
Is The Distributor
Turning?
Value(s)
Check -
Go to Step 2
in
_
Refer to Trou-
bleshooting
-
Rotor
Go to Step 4
SERVICE MANUAL NUMBER 23
Yes No
Go to OBD
System Check
Go to Step 3
Section
Go to Step 25
90-861326--1 MARCH 1999