What Causes a Diesel Engine to Not Exceed 2000 RPM and Experience Idling?
2 Answers
Diesel engine not exceeding 2000 RPM and experiencing idling can be caused by insufficient fuel pump pressure or exhaust issues. Details are as follows: Insufficient Fuel Pump Pressure: When the fuel pump pressure is inadequate, the fuel injection volume is insufficient, preventing the engine from increasing its RPM. Exhaust Issues: Poor exhaust flow reduces the efficiency of the engine's intake and exhaust system, hindering RPM increase. Causes of Idling: When the tangential force on the locomotive's driving wheels exceeds the adhesion force between the wheels and rails, adhesion is disrupted. This results in relative sliding between the wheels and rails at the contact point. Under the driving torque, the wheels rotate rapidly around the axle, leading to idling.
My off-road diesel pickup had the same issue, the idle speed just wouldn't go above 2000 rpm. It happened right after refueling during a long-distance trip. Turned out to be fuel quality problem - I accidentally filled up with water-contaminated diesel. Water-oil separation appeared at the bottom of the tank, and the water got sucked into the fuel lines, causing poor engine fuel delivery. Another critical factor was the extremely dirty diesel filter - I forgot to replace the filter element during last maintenance, and accumulated impurities had clogged about half of the filter screen. The air filter also needed checking, especially since driving in desert areas makes it prone to dust buildup. The intake pipes being clogged with sand was like a person struggling to breathe. The turbocharger inspection showed no problems, but the mechanic mentioned that air leaks in the boost pipes could also cause similar symptoms. Finally, replacing the filter elements + cleaning the fuel system solved the problem, though it took most of the day before I could hit the road again.
