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Home >> Isuzu >> 1989 >> I-Mark LS >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests - CARBURETED >> Fuel Control Components >> Fuel-Cut (Slow-Cut) System
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Fuel-Cut (Slow-Cut) System

  1. Check for trouble codes 22 and 42 before beginning this test. See the TESTS W/CODES - CARBURETED article. Ensure engine is at operating temperature. Connect tachometer.
  2. Run engine at 3500 RPM. Release accelerator. Measure voltage between Black/Green wire harness terminals of solenoid. Fuel-cut solenoid is located on carburetor, near choke heater. See Fig 1 .
  3. If voltage is less than 6 volts, go to step 4). If voltage is more than 6 volts, check for open between fuel-cut solenoid and ECM. If not open, adjust idle switch. If idle switch is okay, problem is with ECM or connector.
  4. Momentarily return throttle to idle and check voltage. If voltage does not change, go to step 5). If voltage rises to more than 6 volts and falls to low level at 2000-2500 RPM, check fuel-cut circuit and idle switch adjustment.
  5. If code 22 or 42 are not stored in ECM, the problem is poorly adjusted idle switch or (A/C) fast idle control diaphragm.
Fig 1: Locating Fuel-Cut (Slow-Cut) Solenoid
G122324Courtesy of ISUZU MOTOR CO.
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