Turbo Engine

Warm engine to operating temperature. Turn ignition switch to "OFF" position. Unplug throttle valve switch harness at connector. Insert fine wire into upper (idle) terminal, then make connections at connector with wire pulled part way out. See Fig 1 .

Fig 1: Fuel-Cut System Test (Turbo)
Courtesy of ISUZU MOTOR CO.
Disconnect throttle position sensor at connector. Use a jumper wire to connect throttle valve switch and the same side of harness. See Fig 1 . Do not connect harness side connector and throttle position sensor with piece of wire in place because a short will result. Start engine and run at 2500-3000 RPM.
Ensure engine speed lowers to about 1250 when battery voltage is applied to wire extending from idle terminal. Engine shake may occur at about 1250 RPM, it is normal during test procedure.

NOTE: Fuel cut is controlled by the throttle position sensor. Fuel injection is controlled by the throttle switch.

FUEL-CUT SYSTEM TEST - TURBO

Test Condition

Speed: MPH

Engine RPM

Idle Contact

Fuel-Cut ⁽¹⁾

15 or More

1500 or More

n/a

Injection

6 or More

n/a

Injection

n/a

OFF

Injection

n/a

1250 or Less

n/a

⁽¹⁾	With throttle position sensor on.