Detroit Diesel — Performing Fuel Troubleshooting Tests
Testing & diagnosis · Fuel system
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Correct torque on the high pressure lines is critical.
- Fuel temperature in the tank no higher than 40°C (104°F).
Procedure
- Run the engine for two to three minutes at rated speed, 1800–2100 rpm.
- Visually inspect all fuel lines, pressure fittings, and components; replace components found damaged or leaking.
- Tighten all high-pressure fittings to 25 N·m (18 lb·ft) and all banjo bolts to 40-50 N·m (30-37 lb·ft).
- Inspect the filter element in the fuel pre-filter; replace if necessary.
- Inspect the filter element in the main fuel filter; replace if necessary.
- Run engine to operating temperature of approximately 82°C (180°F), then shut down.
- Perform the fuel system troubleshooting tests and correct any problems.
- Prime the fuel system (work hand pump until resistance is felt, or crank engine).
Specs & values
- 25 N·m (18 lb·ft) high-pressure fittings
- 40-50 N·m (30-37 lb·ft) banjo bolts
- 82°C (180°F) operating temp
Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.