Diesel engine difficult to start

Here are some of the possible reasons why a diesel engine is difficult to start.

1. 
   The compression in the engine cylinders is low
2. The fuel pump plungers are worn
3. Diesel fuel thickens at low temperatures
4. Blocked injector nozzles, faulty injectors, black exhaust smoke
5. Faulty starter or weak accumulator
6. Faulty glow plug control system and damaged glow plugs
7. Fuel filter contamination

Suggestions

1. If a diesel engine has low compression, starting a warm engine is similar to starting a cold diesel engine, as both scenarios can be challenging. Additionally, the engine start tends to be sluggish rather than immediate. Low compression may occur due to worn cylinders, damaged piston rings, sticking piston rings, gaps or malfunctions in valves, or collapse of the piston top.
   If the piston rings are sticking, it is recommended that you use the Anticarbon product, which is an anti-carbon engine cleaner that penetrates into every cylinder through the glow plugs or the injection nozzles. Before changing the engine oil if is worth remembering that we recommend that you use our Atomex TotalFlush product, an oil system cleaner. If the cylinders and piston rings are only slightly worn carry out a full engine oil system treatment by using our EX120 Revitalizant® for diesel engine or Atomic Metal Conditioner Maximum with 1 Stage Revitalizant® products.
2. Another common reason why starting a warm diesel engine is difficult may be due to worn fuel pump plungers. In this scenario, cold fuel can easily be, however, once the fuel warms up, it becomes more fluid and cannot be pumped in the proper volume needed to start the engine. Slight wear of the fuel pump plungers can be restored through special cleaning agents and subsequent treatment of the diesel engine fuel system with Revitalizant for fuel equipment.

 Here you will find recommended diesel engine fuel system cleaners:

o   VERYLUBE fuel system cleaner (Diesel)

o   Diesel-Lux - complex fuel treatment

o   Multi Cleaner (Diesel) – protection of diesel engine

o   F8 Complex Formula (Diesel) – protection of diesel engine

Here are the recommended XADO gel revitalizing agents to revitalize the worn fuel pump plungers:

o   Revitalizant® EX120 for fuel equipment

o   Atomic Metal Conditioner Maximum Diesel Truck Revitalizant® for fuel equipment

3. The third reason why a diesel engine may be difficult to start is thickening of diesel fuel at low temperatures. If this occurs it is recommended that you add an Antigel, a superconcentrated diesel fuel treatment, which will help to reduce the diesel fuel thickening temperature by 7-12 °С. The product should be added regularly at an ambient temperature not higher than 5 °С.
4. In case the injection nozzles are blocked it is recommended that you use a diesel engine fuel system cleaner. If black exhaust smoke is evident, it indicates a badly contaminated diesel particulate filter (DPF). In this case, the injection nozzles should be checked and, if necessary, changed.
5. If the starter motor is not working properly, it should be repaired. If there is a weak accumulator, this should also be changed or replaced.
6. If the advance injection system has failed, it should be checked and repaired by specialists.
7. if the glow plug control system and heating plugs have failed, this can be solved by running a standard check list. If this routine check reveals issues or irregularities, additional steps—such as troubleshooting, repairs, or more in-depth diagnostics—may be required
8. If the fuel filter is clogged, it should be replaced and the fuel system cleaned regularly with one of our fuel system cleaning agents.