Calibration Test

Connect a reliable calibrated tach-dwell meter to vehicle ignition system. Operate engine at various engine RPMs. See TACHOMETER ALLOWABLE VARIATION . Compare readings between tach-dwell meter and vehicle tachometer. If readings on vehicle do not fall within acceptable range, replace vehicle tachometer.

TACHOMETER ALLOWABLE VARIATION

Engine Speed (RPM) ⁽¹⁾

⁽²⁾ Acceptable Range

750

650-850

2000

1900-2100

3000

2850-3150

4000

3900-4200

5000

4750-5250

6000

5700-6300

7000

6650-7350

⁽¹⁾	Engine speed as measured with tach-dwell meter.

⁽²⁾	Acceptable range for actual vehicle tachometer reading