Engine-Induced Symptoms

Perform the following:

• If engine cranks but will not start (cold), check glow plug module relay and Energize-To-Run (ETR) solenoid. Check fuel delivery and cold idle speed/advance and idle speed. See IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.
• If engine cranks but will not start (at normal operating temperature), check fuel delivery and ETR solenoid.
• If engine stalls, check cold idle speed/advance and idle speed. See IDLE SPEED & MIXTURE in ADJUSTMENTS article in the ENGINE PERFORMANCE Section. Check ETR solenoid.
• If engine misses, determine when miss occurs and isolate miss. Check fuel delivery from nozzle. Check engine compression and crankcase pressure.
• If engine knocks, ensure engine-driven accessories function properly. Ensure engine is not overheating. Determine when engine knock (detonation) occurs and isolate knock. Check fuel delivery from nozzle.
• If engine oil pressure is low, change engine oil and filter. Check oil pressure transducer.
• If engine expels Blue/White smoke (engine at normal operating temperature), ensure coolant thermostat functions properly. Check engine oil level (excess oil in crankcase). Check fuel return lines.
• If engine expels Black smoke, determine under what conditions Black smoke occurs. Check exhaust system for damage or restrictions. Check air intake for restrictions. Check injection nozzles. Check injection pump timing. See 7.3L DIESEL INJECTION TIMING in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.
• If WAIT TO START indicator light is always on, check wiring to indicator for short circuit to ground. Check diesel/warning light module (located behind left side of dash, near fuse block).
• If WAIT TO START indicator light does not come on, check for burned out bulb. Check wiring to indicator for an open circuit.
• If glow plug system is inoperative, check glow plug(s). check glow plug system wiring harness and connectors. Check voltage supply (battery and ignition feed) and ground circuits to diesel/warning light module. Check diesel/warning light module (located behind left side of dash, near fuse block).
• If air leaks in fuel delivery system are present, check for poor fuel hose connections. Check fuel system for bubbles or foam, including fuel filter/water separator. Check fuel flow direction. Flow (bubbles) should flow from fuel filter outlet fitting to fuel injection nozzle return fitting. If dual-tank equipped, check fuel selector valve for proper operation.