47968 Mercury SPRING, TENSION - CHOKE KNOB AND SHAFT

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Schematic
The engine speed/timing sensors provide information to the ECM by generating pulse signals as the timing reference ring rotates past the magnetic pickups on the sensors.The secondary engine speed/timing sensor provides continuous operation of the engine if the primary engine speed/timing sensor fails. The loss of signals from both engine speed/timing sensors will prevent the ECM from actuating the injectors. To prevent any unnecessary down time, correct any problems with the speed/timing circuit as soon as possible.The engine speed/timing sensors are magnetic sensors that provide a frequency that is directly proportional to engine speed (rpm). A unique tooth on the timing reference ring passes by the engine speed/timing sensor. The engine speed/timing sensor produces a duty cycle output. This duty cycle provides the ECM with information on the crankshaft position.Timing calibration is accomplished by installing a probe into the side of the engine block and by performing the "Timing Calibration" on the Caterpillar Electronic Technician (Cat ET). The probe senses a special slot on the crankshaft counterweight. The probe is connected to the ECM through the P26 timing calibration connector on the engine harness.Note: Performing a timing calibration will not increase the available engine power.
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Table 1
Required Special Tools
Part Number Description
6V-2197 Magnetic Transducer (Timing Calibration Probe)
7X-1695 Cable (Timing Calibration)
7X-1171 Transducer Adapter
9S-9082 Engine Turning Tool Test Step 1. Install the 7X-1171 Transducer Adapter
Turn the keyswitch to the OFF position.
Use the 9S-9082 Engine Turning Tool to put either the No. 1 piston or the No. 6 piston at top center. Then rotate the crankshaft in the direction that is opposite of the normal rotation for 60 degrees. Note: Normal engine rotation is counterclockwise as the engine is viewed from the flywheel end. Refer to Illustration 2.
Remove the timing calibration plug from the cylinder block. Note: If the engine is viewed from the flywheel side of the engine, the timing calibration plug is located on the left side. The timing calibration plug is located on the No. 2 cylinder rod pocket.
Install the 7X-1171 Transducer Adapter into the hole for the plug. Results:
OK - Proceed to Test Step 2.Test Step 2. Install the 6V-2197 Timing Calibration Probe on the Engine
If the crankshaft is not in the correct position when the 6V-2197 Timing Calibration Probe is installed, the probe will be damaged when the engine is started.
Put the 2D-6392 O-Ring Seal on the end of the timing calibration probe. Note: A small amount of clean engine oil will allow the seal to slide onto the sensor more easily.
Push the sensor through the adapter until the sensor contacts the outermost portion of the crankshaft counterweight. Move the O-ring seal downward against the adapter.
Withdraw the sensor 1.0 mm (0.04 inch) and hand tighten the nut on the adapter sleeve in order to secure the magnetic pickup in place.
Connect the 6V-2197 Timing Calibration Probe to the 7X-1695 Cable. Results:
OK - Proceed to Test Step 3.Test Step 3. Start the Engine and Allow the Coolant to Reach Operating Temperature
Start the engine and run the engine at low idle until the engine is at normal operating temperature.
Check for active diagnostic codes. Use the procedures in this manual for troubleshooting. Repair any active diagnostic codes before you check the calibration. The engine must not have any diagnostic conditions that are present during the timing calibration except the 261-13 diagnostic code: Results:
OK - Proceed to Test Step 4.Test Step 4. Connect Cat ET
Connect Cat ET to the service tool connector.
After the engine has warmed up, access the "Timing Calibration" screen on Cat ET. Access the following display screens in order:
"Service"
"Calibrations"
"Timing Calibration Screen"
Disconnect the J26/P26 connector. Note: The P26 timing calibration connector is located near the ECM. Refer to Troubleshooting, "Sensors and Electrical Connectors" for the P26 connector location.
Connect the 7X-1695 Cable to the P26 timing calibration connector.
Ensure that all of the following connections are made correctly:
Timing calibration probe
Cables for Cat ET and the communication adapterResults:
OK - Proceed to Test Step 5.Test Step 5. Calibrate the Speed/Timing SensorNote: Engine speed will be automatically adjusted.
To calibrate the timing to the correct setting, select "Continue" on Cat ET. Wait until Cat ET indicates that the timing is "CALIBRATED". Note: If the display on Cat ET reads "CALIBRATION UNSUCCESSFUL", recheck the tool installation and tool operation and try again. If the crankshaft and camshaft gears have been reassembled incorrectly, the sensor will not calibrate.Note: Do not exit the "Timing Calibration" screen on Cat ET until you have disconnected the timing calibration probe and you have reconnected the J26/P26 connector.Expected Result:The timing calibration procedure was completed successfully.Note: Diagnostic codes will be generated for the primary engine speed/timing sensor if J26/P26 is not reconnected before exiting the "Timing Calibration" screen on Cat ET.Results:
OK - The timing calibration procedure was completed successfully.STOP
Not OK - Repair: Perform the following procedure:
Verify that the engine speed was stable during the testing ( 50 rpm). If the engine speed was unstable or the engine speed could not be controlled within 50 rpm because of mechanical factors or electrical factors, refer to Troubleshooting, "Engine Misfires, Runs Rough or Is Unstable".
If all of the problems have been corrected but the timing can not be calibrated, check the cable of the 6V-2197 Timing Calibration Probe and check the probe in order to verify that the probe is not bent. Verify that the probe is installed correctly before you restart this procedure. STOP