You do not need the full parts book in your head. These seven groups cover most “it will not pull” complaints.
- Air filter and turbo — air in, boost out.
- Fuel filters — pressure and cleanliness.
- Injectors — how that fuel is delivered.
- ECM — the limits and the fault memory.
- Water pump — coolant flow.
- Oil filter and pump — the film on the bearings.
- Pistons and liners — what is left when the rest was ignored.
Diagnose in that order when you can. It is cheaper than opening the engine because the exhaust looked dark.
When you are ready to order, the engine serial selects the correct member of each group.