Home     Email     Contact     Affiliates    Links    Service    Troubleshooting    Core Criteria
Diesel Ad Rollngo Caddy
Engine runs rough or misfires



Conditions only occurs at idle

See - Engine runs rough at idle

Engine is cold

Allow the engine to warm up to operating temperature. If engine will not reach operating temperature see manual.

Fuel injection lines are leaking

Inspect/correct the leaks in the high pressure lines, fittings, or delivery valve gaskets.

Fuel supply inadequate

Check the flow through the filter to locate the source of the restriction

Air in the fuel system

Bleed the fuel system and check for suction leaks

Malfunctioning fuel return overflow valve

Check/replace the return overflow valve

Fuel transfer pump malfunctioning

Check/replace the fuel transfer pump

Fuel Supply restricted

Clean the pre-filters and screens and check the fuel line for restrictions.

Fuel contaminated

Verify by operating the engine with clean fuel from a temporary tank.

Valves incorrectly adjusted (valves are not sealing)

Check and adjust the valves

Injection pump timing

Check and adjust the timing of the injection pump to the engine manufacturer's specifications.

Engine compression is low

Perform the compression check to identify the malfunction.

Injectors worn or malfunctioning

Check the injectors and replace any malfunctioning injectors

Fuel injection pump malfunctioning/delivery valves are malfunctioning

Remove the fuel injection pump and repair or replace as necessary

Camshaft is out of time

Check/correct the gear train timing alignment

Camshaft, tappets, or push rods are damaged

Inspect the camshaft and tappets