Possible Causes & Corrections

Check the following items:

• Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
• Inspect fuel delivery system. Check for no fuel to injection pump or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
• Observe the Fuel Rail Pressure (FRP) sensor and the fuel pressure regulator commanded percent at idle. FRP should be near 40 MPa, and commanded percent should be near 40 percent. If the command is high, a fuel pressure or sensor exists.
• Inspect the Crankshaft Position (CKP) sensor reluctor wheel. Remove the CKP sensor and attempt to move the reluctor wheel front to back or side to side with a probe. If there is any movement the reluctor wheel retaining bolts are loose.
• Check air filter, turbocharger and air intake system for restriction.
• Check for incorrect pump timing. See appropriate SELF-DIAGNOSTICS article.
• Check oil level and quality.
• Inspect fuel quality.
• Check control module grounds for correct locations, tight and clean connections. See WIRING DIAGRAMS article.
• Inspect the engine speed signal circuit for high resistance.
• Check transmission for proper shifting and Torque Converter Clutch (TCC) system for proper operation.
• Check engine for low compression. Check for incorrect valve timing, incorrect or worn camshaft.
• Inspect fuel delivery system. Check for low fuel pressure, restriction or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
• Check charging system output. Repair charging system if voltage is less than 9 volts or more than 16 volts.
• Check A/C for proper operation.
• Check for worn or damaged turbocharger turbine wheel, shaft or compressor wheel.
• Check for air leaks or restrictions in intake air system or manifold.
• Check for a restricted or leaking exhaust system.
• Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.