899912035 Mercury TAPPET, (3.721)

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Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
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Left side engine view (1) J1/P1 ECM connectors
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Right rear engine compartment of scraper (2) Ether solenoid
Thoroughly inspect the ECM connectors (1) and solenoid (2). Also inspect the circuit from the ECM connector to the ether injection solenoid. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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Terminal locations at the P1 ECM connector for the ether injection system (P1-20) Ether injection solenoid (P1-18) Solenoid return
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Harness connector for the ether injection solenoid (1) Ether injection solenoid (2) Solenoid return
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the ether injection system.
Check the torque of the allen head screws for the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the ether injection solenoid to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and the wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Verify that the original problem is resolved.STOPTest Step 2. Check the Ether Canister for Ether
Turn the keyswitch to the OFF position.
Remove the ether canister from the ether valve. Determine if the canister is empty.Expected Result:The ether canister is not empty.Results:
OK - The ether canister is not empty. Do not install the ether canister. Proceed to Test Step 3.
Not OK - The ether canister is empty.Repair: Replace the empty ether canister with a full ether canister. Verify that the original problem is resolved.STOPTest Step 3. Check the Resistance of the Ether Injection Solenoid
Turn the keyswitch to the OFF position.
Disconnect connectors J504/P504 for the ether injection solenoid.
Measure the resistance of the ether injection solenoid across the terminals of the J504 connector.Record the resistance of the ether injection solenoid. The correct resistance of the ether injection solenoid is approximately 20 Ohms.Expected Result:The resistance of the ether injection solenoid is approximately 20 Ohms.Results:
OK - The resistance of the solenoid is approximately 20 Ohms. The solenoid is OK. Proceed to Test Step 4.
Not OK - The resistance of the solenoid is not approximately 20 Ohms.Repair: The internal windings of the solenoid are open or shorted. Replace the ether injection solenoid. Install the ether canister. Verify that the repair resolved the original problem.STOPTest Step 4. Check the Return Circuit at the Ether Injection Solenoid
Disconnect the J1/P1 connectors.
Measure the resistance from terminal P504-2 (solenoid return) to P1-18 (soleniod return).
Connect the J504/P504 connectors.Expected Result:A short circuit exists in the circuit between terminals P504-2 (solenoid return) and P1-18 (soleniod return).Results:
OK - A short circuit exists between terminal P504-2 and terminal P1-18. Proceed to Test Step 5.
Not OK - A short circuit does not exist between terminals P504-2 and terminal P1-18.Repair: There is a problem in the solenoid's return circuit. There is a problem with the wiring between the connector for the ether injection solenoid and the P1 connector. The problem may be with a harness connector. Repair the connectors and/or the wiring. Replace parts, if necessary. Verify that the repair resolved the original problem.STOPTest Step 5. Check the Circuit Resistance at the ECM Connector
Disconnect the J1/P1 connectors.
Measure the resistance from terminal P1-20 (ether injection solenoid) to P1-18 (ether soleniod return).The correct measurement for the circuit is approximately equal to the resistance measurement of the ether injection solenoid.Expected Result:The measurement of the circuit is approximately equal to the resistance that was recorded for the ether injection solenoid.Results:
OK - The resistance of the circuit is approximately equal to the resistance of the solenoid. There may be a short to another wire in the harness. Proceed to Test Step 6.
Not OK - The circuit resistance is not approximately equal to the resistance of the solenoid.Repair: There is a problem in the harness from the ECM to the connector for the ether injection solenoid. There may be a problem with a connector for the harness. Repair the connectors and/or the wiring. Replace parts, if necessary. Verify that the repair resolved the original problem.STOPTest Step 6. Check for a Short to Another Wire at the ECM Connectors
Disconnect connectors J504/P504 for the ether injection solenoid.
Disconnect the J2/P2 connectors.
Measure the resistance from terminal P1-20 (ether injection solenoid) to each of the wires that are in connectors P1 and P2.The correct measurement to each terminal is an open circuit.Expected Result:The measurement to each terminal in the P1 and the P2 connectors is an open circuit.Results:
OK - An open circuit exists to all of the other terminals that are in the ECM connectors.Repair: There is a problem with the ECM. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".STOP
Not OK - A short circuit was measured in one of the terminals in an ECM connector.Repair: There is a short circuit to one of the wires tha