Navistar engine will not rise at 2000 rpm.

What you want to ask is why the Navistar engine doesn't rise at 2000 rpm. The reason for this is the following：

1. Oil supply problem: due to the blockage of oil circuit or fuel filter, the oil supply will be insufficient and the engine speed will be affected.

2. Air supply problem: The air filter is blocked or the air inlet is blocked, which will lead to insufficient air supply, thus affecting the engine speed-up.

3. Ignition system problem: aging of spark plug or failure of ignition coil will lead to poor ignition and affect the improvement of engine speed.

4. Failure of engine running parts: serious wear of valves or piston rings will lead to the decrease of cylinder pressure and affect the increase of engine speed.

5. Engine electronic control system failure: The failure of the engine electronic control unit will lead to the abnormal working state of the engine, thus affecting the improvement of engine speed.