N14 Base Engine Troubleshooting and Repair Manual – Smoke, Black — Excessive (PT)

Intake manifold pressure (boost) is below specification

Refer to the Intake Manifold Pressure (Boost) is Below Normal symptom tree.

Air intake or exhaust leaks

Inspect the air intake and exhaust systems for air leaks. Refer to Procedure 010-024.

Fuel drain line restriction

Check or replace the fuel lines, check valves, or tank vents as needed. Refer to Procedure 006-012.

Air intake system restriction

Check the air intake system for restriction. Refer to Procedure 010-031.

Exhaust system restriction

Check the exhaust system for any restrictions. Refer to Procedure 011-009.

Fuel grade is not correct for the application or the fuel quality is poor

Operate the engine from a tank of high-quality fuel. Refer to Fuel for Cummins Engines, Bulletin 3379001.

PT fuel pump rated or no-air fuel pressure is above specification

Remove the fuel pump and check the calibration. Refer to Procedure 005-016 and PT Fuel Pump Rebuild and Calibration Manual, Bulletin 3379084.

Fuel rate and fuel pressure are high and intake manifold pressure is okay

Remove the fuel pump and check the calibration. Refer to Procedure 005-016 and PT Fuel Pump Rebuild and Calibration Manual, Bulletin 3379084.

Fuel rate is high, fuel pressure is okay or low, and intake manifold pressure is okay

Remove the injectors and check the calibration. Refer to Procedure 006-026.

Turbocharger wheel clearance is out of specification

Check the radial bearing clearance and axial clearance. Inspect the turbocharger. Repair or replace the turbocharger if necessary. Refer to Procedures 010-038 and 010-047.

Overhead adjustments are not correct

Measure and adjust the overhead settings. Refer to Procedure 003-004.

Injector cup is damaged or is not correct

Check the injector cups for damage and for correct part numbers. Refer to Procedure 006-026.

Turbocharger oil seal is leaking

Check the turbocharger compressor and turbine seals. Refer to Procedures 010-040 and 010-049.