Install tachometer. Tachometer must be connected to proper terminals. See IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.
CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.
Start engine and warm to normal operating temperature. Ensure all accessories are off. Gradually increase engine RPM to at least 2500 RPM.
Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily (fuel cut RPM) and then resumes operating (fuel return RPM).
Ensure fuel return RPM is within specification. See FUEL CUT SYSTEM SPECIFICATIONS table. Shut engine off and disconnecttachometer.

FUEL CUT SYSTEM SPECIFICATIONS

Application

Fuel Cut RPM

Fuel Return RPM

Pickup & 4Runner

2.4L

2WD With A/T ⁽¹⁾

1300

1000

All Others

1900

1600

3.0L

A/T

1800

1500

M/T

1600

1300

⁽¹⁾	Check with brake pedal depressed and brake lights on.

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.

Safety Warning

Fuel Cut System