Fuel-Cut System

Warm engine to operating temperature. Turn ignition switch to the "OFF" position. Unplug throttle valve switch wire connector.
NOTE: Throttle valve switch and throttle position sensor is mounted on the throttle body throttle shaft. M/T models use a throttle valve switch. A/T models use a throttle position sensor that is combined with a throttle valve switch.
Insert a fine wire into upper (idle) terminal of throttle valve connector. With fine wire pulled part way out, reconnect throttle valve switch connector. See Fig 1 .
On A/T models, disconnect throttle position sensor connector. Using a jumper wire, connect jumper wire between 2 terminals on harness side of connector. See Fig 2 .
CAUTION: DO NOT reconnect throttle position sensor and with wires in place.
On all models, start engine and run at 2000-2500 RPM. Connect battery voltage to fine wire that was inserted into throttle valve switch connector.
When battery voltage is applied, engine speed should lower to approximately 1250 RPM. Engine surging may occur, which is normal during test procedure.

NOTE: On A/T vehicles, fuel cut-off system is controlled by throttle position sensor during deceleration. Fuel injection reactivation is controlled by throttle valve switch. On M/T vehicles, fuel cut-off and fuel injection reactivation is controlled by throttle valve switch.

FUEL-CUT SYSTEM TEST - (IMPULSE)

Condition

Speed (MPH)

Engine (RPM)

Idle Contact

Fuel-Cut ⁽¹⁾

15 or More

1500 or More

Fuel-Cut ⁽¹⁾

1500 or More

Injection

6 or More

N/A

Injection

N/A

Off

Injection

N/A

1250 or Less

N/A

⁽¹⁾	With throttle position sensor or throttle valve switch on.

Fig 1: Throttle Valve Switch Connector Terminal I.D.

Courtesy of ISUZU MOTOR CO.

Fig 2: TPS Sensor & Switch Connector Terminal I.D. (A/T models)

Courtesy of ISUZU MOTOR CO.