Possible Cause

Restricted air intake.

Plugged fuel filter.

Faulty PCM operation.

Improper fuel return system.

Restricted tank-to-pump fuel supply.

Incorrect or contaminated fuel.

Faulty EGR operation.

Worn camshaft or valves. Repair as necessary

Nozzle or glow plug compression leaks.

Plugged nozzle.

Worn or damaged turbocharger turbine wheel,

shaft or compressor wheel (if equipped).

Faulty TCC or shift points.