Test Example - Mercury MerCruiser MCM 454 Mag MPI Service Manual

GENERAL SYSTEM DIAGNOSTICS
NOTE: The entire test should not be repeated more than once without running the engine
to prevent flooding. (This includes any retest on faulty injectors.)

Test Example

Cylin-
der
1st.
Reading
2nd
Reading
Amount
of Drop
Index
Page 5E-50
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300ms
a
a - Injector
b - 1st Reading (Initial Pressure)
c - Fuel Pressure Gauge
d - 2nd Reading (Pressure After Drop)
1 2
38 PSI 38 PSI
(262 kPa) (262 kPa)
19 PSI 17 PSI
(131 kPa) (117 kPa)
19 PSI 21 PSI
(131 kPa) (145 kPa)
Rich
(Too
OK
Much
Fuel
Drop)
b
d
EXAMPLE
3 4 5
38 PSI 38 PSI 38 PSI
(262 kPa) (262 kPa) (262 kPa)
21 PSI 19 PSI 19 PSI
(145 kPa) (131 kPa) (131 kPa)
17 PSI 19 PSI 19 PSI
(117 kPa) (131 kPa) (131 kPa)
Lean
(Too
OK OK
Little
Fuel
Drop)
SERVICE MANUAL NUMBER 23
c
6 7 8
38 PSI 38 PSI 38 PSI
(262 kPa) (262 kPa) (262 kPa)
19 PSI 19 PSI 19 PSI
(131 kPa) (131 kPa) (131 kPa)
19 PSI 19 PSI 19 PSI
(131 kPa) (131 kPa) (131 kPa)
OK OK OK
90-861326--1 MARCH 1999