Calibration Test
Connect a reliable calibrated tach-dwell meter to vehicle ignition system. Operate engine at various engine RPM (measure with tach-dwell meter). See TACHOMETER ALLOWABLE VARIATION table. 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) |
Acceptable Range (RPM) |
| 1000 |
900-1100 |
| 2000 |
1875-2125 |
| 3000 |
2850-3150 |
| 4000 |
3850-4150 |
| 5000 |
4850-5150 |
| 6000 |
5820-6180 |
| 7000 |
6790-7210 |