815539T Mercury THROTTLE CAM

Illustration 1 g00664608
Use the following procedure in order to calibrate the timing of the TCM with the timing of the magneto. This procedure is also used in order to troubleshoot the "Magneto Out of Calibration" (diagnostic 08). The magneto timing is adjusted by physically rotating the position of the magneto. Use this procedure in order to install the magneto and set up the magneto. Also see Systems Operation/Testing and Adjusting, SENR4604, "Magneto Installation".A magneto calibration must be performed when any of the following conditions exist:
The magneto has been rotated.
A new magneto has been installed.
A new TCM has been installed.Test Step 1. Start the Engine.
If there is a fault, repower the TCM in order to clear the fault.
Connect the DDT to the TCM. Refer to Troubleshooting, "Connecting the DDT to the TCM".
Place the TCM in magneto calibration mode.
Scroll to the "MAG CAL MENU" screen (menu 4) on the DDT. Press the "Select Func" key in order to select the "Magneto Calibration" mode.In the "Magneto Calibration" mode, the "Select Func" key will alternate between "Actual Engine Timing" (screen 40) and "Detonation Level" (screen 41).
Start the engine.
Idle the engine above 700 rpm.
The "Displayed Timing" on the DDT is the full advanced magneto timing.
Allow the engine speed to stabilize.
If the maximum advance timing needs to be changed, perform the following steps:
Loosen the magneto fastener bolts and adjust the timing by rotating the magneto to six degrees ahead of the most advanced desired setting. Refer to the Systems Operation/Testing and Adjusting, SENR4604, "Timing and Fuel Charts".
Tighten the magneto fastener bolts.
Press the "Select Mode" button in order to exit the magneto calibration.
To program the desired timing with the DDT, refer to Troubleshooting, "Programming the TCM".
Stop the engine.
Reset the system.
Start the engine.Note: Check that the TCM is NOT in the "Magneto Calibration" mode.Expected Result:The engine starts. The "MAGNETO OUT OF CALIBRATION" LED is not illuminated.Results:
OK - The magneto is calibrated with the TCM. Stop.
Not OK - The "MAGNETO OUT OF CALIBRATION" LED is illuminated. Proceed to test step 2.Test Step 2. Check for Connector Damage.
Remove the power from the TCM.
Check the following components: connectors and wiring for the TCM, interconnect harness and Crank Angle Sensor (CAS). Check the components for the following problems: damage, corrosion, abrasion and incorrect attachment. Refer to Troubleshooting, "Inspecting Electrical Connectors".Expected Result:The connectors and wiring are in good condition.Results:
OK - The components are in good condition. Proceed to test step 3.
Not OK - The components require service.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Reconnect all of the connectors. Stop.Test Step 3. Check Cylinder 1.
Connect a timing light to cylinder number 1.
Reset the system.
Start the engine.
Monitor the timing light for cylinder number 1.Expected Result:The timing light indicates that the cylinder is working.Results:
OK - The cylinder is firing. Proceed to test step 4.
Not OK - The cylinder is not firing.Repair: This signal is required for calibration. The magneto has failed and/or part of the ignition has failed. Check the following components for damage: wiring harness for the ignition, connection for the transformer, transformer for cylinder 1, extender and spark plug. Replace any faulty component. Reset the system and attempt to calibrate the magneto. If the fault returns, replace the magneto. Stop.Test Step 4. Check the CAS.
Disconnect the CAS from the engine harness.Note: Be sure that you measure the resistance at the sensor connector. Do not measure the resistance at the harness connector.
Use the 4000 ohm scale to measure the resistance between pin A and pin B at the sensor connector.Expected Result:The resistance is between 100 and 600 Ohms.Results:
OK - The sensor is OK. Proceed to test step 5.
Not OK - Repair: Replace the CAS. Stop.Test Step 5. Check the Harness.
Connect the CAS to the engine harness.
Disconnect the TCM from the engine harness.
Measure the resistance at the harness connector for the TCM. Use the 4000 ohm scale on the multimeter to measure the resistance between pin L and pin N.Expected Result:The resistance is between 100 and 600 ohms. The value is equal to the reading from test step 4.Results:
OK - The harness is OK. Proceed to test step 6.
Not OK - There is a problem in the wiring harness.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Reconnect all of the connectors. Stop.Test Step 6. Check the Clearance Between the CAS and the Flywheel.
Disconnect the CAS from the engine harness.
Mark the position of the CAS.
Loosen the locknut.
Turn the sensor clockwise until the sensor contacts the flywheel.Record the number of turns that are required to make contact. One-half to three quarters of a turn (180 to 270 degrees) are required to obtain the proper clearance.
Remove the sensor from the flywheel housing.
Inspect the sensor for damage and for metal filings on the magnet.
Manually rotate the flywheel. Inspect the surface of the flywheel along the path for the CAS. Repair any nicks or scratches on the surface.
Install the CAS.
Turn the sensor clockwise until the sensor contacts the flywheel face.
Turn the sensor in a counterclockwise direction for approximately one-half to three quarters of a turn (180 to 270 degrees).Note: Do not allow the sensor to move when you tighten the locknut.
Tighten the locknut.
Connect the CAS to the engine harness.Expected Result:The magnetic tip does not have an excessive amount of metal debris. The surface of the flywheel is in good condition. The clearance for the CAS is OK.Results:
OK - The components are in good condition. The components are properly installed.Repair: Reset the system. Restart the engine. If the fault recurs, replace the CAS. Then reset the system and restart the engine. If the fault recurs, replace the TCM. Stop.
Not OK - The clearance was incorrect.Repair: Install the sensor with the proper clearance. Reset the system. Restart the engine. If the fault returns replace the CAS. Then reset the system and restart the engine. If the fault recurs, replace the TCM. Stop.
Not OK - The sensor has been damaged.Repair: Replace the sensor. Install the new sensor with the correct clearance. Stop.