Knock Sensor - Mercury MerCruiser MCM 454 Mag MPI Service Manual

MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY

Knock Sensor

NOTE: The 7.4L MPI has a knock sensor mounted on the port and starboard sides of the
engine block.
REMOVAL
1. Disconnect electrical connector at knock sensors located just ahead of starter motor.
Starboard Side Shown
2. Remove both knock sensors from engine block.
CLEANING AND INSPECTION
1. Clean knock sensors with a dry cloth, paying special attention to threads on base.
2. Inspect surfaces of knock sensors for signs of wear or physical damage.
INSTALLATION
IMPORTANT: If installing a new knock sensor, be sure to replace it with an identical
part. Knock sensors are very sensitive and designed for each specific application.
IMPORTANT: In the following step, it is very important that the knock sensor be
torqued to the precise specification. Incorrect torquing will result in unsatisfactory
performance. DO NOT use sealer on threads.
Index
Page 5C-52
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Refer to "Precautions" in this section, BEFORE proceeding.
a - Knock Sensor
NOTICE
a
SERVICE MANUAL NUMBER 23
75678
90-861326--1 MARCH 1999