Efi - Mercury MerCruiser MCM 4.3L ALPHA Service Manual

MAINTENANCE

EFI

1. Connect timing light to number 1 spark plug wire.
2. Start engine and run at 1300 rpm until it reaches normal operating temperature.
3. Stop engine and connect the scan tool or timing tool to the DLC connector on the EFI
wiring harness.
4. Start engine, allow rpm to stabilize.
NOTE: MEFI-1 models only, manually adjust remote control throttle lever to get 1200 engine
rpm.
NOTE: MEFI-3 models only, ECM will automatically adjust engine rpm to approximately
1200 rpm when put in the service mode on a scan tool or when using the timing tool.
5. Check ignition timing. If incorrect, rotate the distributor until timing is correct. Torque
clamping screw to 18 lb-ft (25 Nm).
6. Recheck ignition timing.
7. Disconnect scan tool or timing tool from DLC connector.
8. If required, return remote control throttle lever to idle position and shut off engine.
9. Restart engine, increase rpm to 1300 then return to idle position slowly. Ensure that
engine returns to idle rpm. Readjust throttle cable, if required.
10. Shut engine off.
Index
Page 1B-28
SERVICE MANUAL NUMBER 25
90-861328--1 NOVEMBER 1999