Important:
| • | Cranking speed is critical for a diesel engine to start, whether
the engine is hot or cold. Some tachometers are not accurate at cranking speed.
The primary method of testing cranking speed or determining the accuracy
of a tachometer is to use a scan tool. |
| • | Ensure that the vehicle's batteries are in good condition, and
fully charged, prior to performing this test. |
- Remove the fuel solenoid fuse.
- Install the scan tool.
- Crank the engine for 2 to 4 seconds. This will allow the starter
to reach it's maximum performance.
- Observe the engine RPM reading on the scan tool.
| • | The minimum cold cranking speed required for the 6.5L diesel engine
is 100 RPM. |
| • | The minimum hot cranking speed required for the 6.5L diesel engine
is 180 RPM. |
| • | The actual cranking speed needed for starting will vary depending
on the condition of the engine mechanical components (compression), and
the condition of the fuel system components (fuel injection pump operating
pressure, and fuel injection nozzles cracking pressure and spray pattern). |
- Observe the engine RPM reading on the tachometer (if desired).
