1997 Cadillac Eldorado BaseFACTORY OEM SERVICE PROCEDURE

Injector Leak Test

  1. Turn engine off. Relieve fuel pressure. Access fuel injector harness connector. Connect Fuel Injector Tester (J-39021) to vehicle battery and to a fuel injector. If coolant temperature is 50-95°F (10-35°C), go to next step. If coolant temperature is not 50-95°F (10-35°C), go to step 5).
  2. Set fuel injector tester's amperage supply selector switch to COIL TEST 0.5 AMP position. Connect a Digital Volt-Ohmmeter (DVOM) to fuel injector tester. Set DVOM to tenths scale (0.0).
  3. Ensure engine coolant temperature is 50-95°F (10-35°C). Press PUSH TO START TEST button. Observe DVOM. Voltage reading may climb during test. Record lowest voltage displayed immediately after activation.
  4. Perform voltage reading on all injectors. If voltage reading is erratic or falls out of specified range, perform injector balance test or replace faulty injector. See INJECTOR TEST VOLTAGE RANGE table or FUEL INJECTOR BALANCE TEST.
  5. Press PUSH TO START button on fuel injector tester. Observe DVOM. Voltage reading may climb during test. Record lowest voltage displayed immediately after activation. Perform voltage reading at least twice on all injectors.
  6. If voltage reading is erratic or is greater than 9.5 volts, replace affected fuel injector. If voltage reading is not erratic or not greater than 9.5 volts, go to next step.
  7. From recorded voltages (except readings greater than 9.5 volts), identify highest voltage reading and subtract from the other recorded voltages. If subtracted value is greater than 0.6 volts, replace affected fuel injector. If subtracted value is less than 0.6 volts, perform injector balance test. See FUEL INJECTOR BALANCE TEST.
INJECTOR TEST VOLTAGE RANGE

Application Volts
4.6L 5.7-7.0
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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