Hard to Start

DEFINITION: The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but immediately dies.

PRELIMINARY CHECKS

- Refer to Important Preliminary Checks. Testing and Inspection
- Make sure the driver is using the correct starting procedure.

SENSOR CHECKS

- Check the Engine Coolant Temperature (ECT) sensor using the scan tool to compare the engine coolant temperature with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5°greater or less than the ambient air temperature on a cold engine, check for a high resistance in the coolant sensor circuit or the sensor itself.

FUEL SYSTEM CHECKS

- Check the Supply to injection pump. Refer to Fuel Supply System Check. Diesel MFI Pump
- Check for air in fuel system. Refer to Fuel Supply System Check.
- Check the fuel return from injection pump. Refer to Fuel Return System Diagnosis. Testing and Inspection
- Check the engine shutoff solenoid operation. Refer to Control Module Systems. P0215
- Check the fuel injection nozzles. Refer to Injection Nozzles. Testing and Inspection
- Check the fuel tank cap vent.
- Check for an internal injection pump problem. Refer to Fuel Injection System. Service and Repair

ELECTRICAL SYSTEM CHECKS

- Check glow plug operation. Refer to Glow Plug System Check. Testing and Inspection
- Check for slow cranking speed.

AIR INTAKE SYSTEM CHECKS

- Check the air cleaner and air intake ducts for a restriction.
- Check for a restriction in turbo charger inlet duct.
- Check for a restriction in the intake manifold.

EXHAUST SYSTEM CHECK

- Check the exhaust system for possible restriction. Refer to Exhaust System.

ENGINE MECHANICAL CHECKS
Check the engine for the following:

- Improper valve timing.
- Low compression.
- Bent pushrods.
- Worn rocker arms.
- Broken or weak valve springs.
- Worn camshaft lobes.

ADDITIONAL CHECKS

- Check for no crank signal. Refer to Diagnostic Tables. Testing and Inspection
- Check the Service Bulletins for control module software updates.