Mercury Optimax 115 Service Manual page 69

IGNITION
Symptom
1. Engine cranks but will not
start (continued)
2. Engine cranks, starts and
stalls
Page 2A-16
DFI Troubleshooting Guide (continued)
Cause
1.9 ECM not functioning
2.0 Low air pressure in rail
2.1 Low fuel pressure in rail
2.2 Abnormally high friction in
engine
2.3 Air in fuel system/lines
2.4 TPS malfunction
2.5 Remote control to engine
harness connection is poor
Action
Injection System:
Listen for injector "ticking" when
cranking or connect spare injector
to each respective harness. Tick-
ing should start after 2 cranking
revolutions.
Ignition System:
– Check for proper operation by
using Inductive Timing Light
91-99379.
– Check battery voltage
(RED/YEL Lead) @ ignition
coils.
– Check for blown fuse (C15).
– Check battery voltage to fuse
from main power relay
(PURPLE Lead).
– Check for shorted stop wire
(BLK/YEL).
– Check crank position sensor
setting [0.015 in. – 0.040 in.
(0.38mm – 1.01mm)] from
flywheel or for defective crank
position sensor.
– Defective ECM.
Power Supply:
Clean and inspect remote control
male and female harness connec-
tors.
See 1.2
See 1.2 and 1.3
Check for scuffed piston or other
sources of high friction.
See 1.3 Crank and start engine
several times to purge.
Check motion of throttle arm. Stop
nuts should contact block at idle
and WOT. Check TPS set-up. Must
connect DDT with adapter harness
(84-822560A5) to ECM.
Clean and inspect male and fe-
male connectors.
90-855347R1 JANUARY 1999