91821 Mercury SPRING

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Fuel injector
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Schematic for the injector solenoid circuit
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Fuel injector harness connector
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Connector in the valve mechanism cover
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Pin locations for the injectors on the P2 connector (57) Injector Cylinder (No. 1) (35) Injector (No. 1 Cylinder Return) (58) Injector Cylinder (No. 2) (34) Injector (No. 2 Cylinder Return) (59) Injector Cylinder (No. 3) (33) Injector (No. 3 Cylinder Return) (64) Injector Cylinder (No. 4) (8) Injector (No. 4 Cylinder Return) (63) Injector Cylinder (No. 5) (7) Injector (No. 5 Cylinder Return) (62) Injector Cylinder (No. 6) (6) Injector (No. 6 Cylinder Return)Test Step 1. Inspect Electrical Connectors and Wiring
Electrical shock hazard. The electronic unit injector system uses 67-73 volts.
Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned OFF.
Thoroughly inspect connector P2. Thoroughly inspect the connectors at the valve cover base. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with injector solenoids.
Check the screw for the ECM connector for the correct torque of 5.0 N m (44 lb in).
Check the harness and wiring for abrasion and for pinch points from the injectors to the ECM.Expected Result:All connectors, pins, and sockets are correctly coupled and/or inserted and the harness is free of corrosion, of abrasion and of pinch points.Results:
OK - The harness is OK. Proceed to Test Step 2.
Not OK - There is a fault in the connectors and/or the harness.Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are correctly coupled.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check for Logged Diagnostic Codes that are Related to the Injector Solenoids
Connect the electronic service tool to the diagnostic connector.
Turn the keyswitch to the ON position.
Check for logged diagnostic codes that are related to the injector solenoids on the electronic service tool.Expected Result:One or more diagnostic codes that are related to the injector solenoids have been logged:
1-5 Cylinder #1 Injector current below normal
1-6 Cylinder #1 Injector current above normal
2-5 Cylinder #2 Injector current below normal
2-6 Cylinder #2 Injector current above normal
3-5 Cylinder #3 Injector current below normal
3-6 Cylinder #3 Injector current above normal
4-5 Cylinder #4 Injector current below normal
4-6 Cylinder #4 Injector current above normal
5-5 Cylinder #5 Injector current below normal
5-6 Cylinder #5 Injector current above normal
6-5 Cylinder #6 Injector current below normal
6-6 Cylinder #6 Injector current above normal Results:
OK - One or more diagnostic codes have been logged. Proceed to Test Step 3.
Not OK - No diagnostic codes have been logged. Proceed to Test Step 3.Test Step 3. Use the "Injector Solenoid Test"
Start the engine.
Allow the engine to warm up to the normal operating temperature.
Stop the engine.
Turn the keyswitch to the ON position.
Access the "Injector Solenoid Test" by accessing the following display screens in order:
"Diagnostics"
"Diagnostic Tests"
"Injector Solenoid Test"
Activate the test.Note: Do not confuse the "Injector Solenoid Test" with the "Cylinder Cutout Test". The "Cylinder Cutout Test" is used to shut off fuel to a specific cylinder while the engine is running. The "Injector Solenoid Test" is used to actuate the injector solenoids while the engine is not running. The click of the injector solenoids should be heard in order to determine that the circuit is functioning correctly.
As each solenoid is energized by the ECM, an audible click can be heard at the valve cover.Expected Result:All cylinders indicate "OK".Results:
OK - Th