- Among the possible reasons is the malfunction of fuel pump caused by high pressure. After warming up of the fuel reducing of its viscosity and increasing of hydraulic losses occur. In this case the pressure decreases which lead to improper transfer of fuel to the combustion chamber.
- Problematic warm start of the engine may also be caused by malfunction of the temperature sensor of one of the injection nozzles. By the cold start of the engine the sensor commands to change the injector spray angle to warm up fuel. In case of failure of the sensor, it gives the same commands by warm and cold start. This may lead to overfueling, vapour locks and problematic engine start.
If there are worn plunger pairs of diesel engine high pressure fuel pump, it is not necessary to replace them. In this case you should conduct complete fuel system flush by adding one of the following products into the fuel tank:It is recommended to introduce the following products after flushing the system in order to restore worn plunger pairs:
- VERYLUBE Fuel system cleaner
- MultiCleaner for diesel engine
- XADO Revitalizant® EX120 for fuel equipment
- XADO Atomic Metal conditioner Maximum Diesel Truck Revitalizant® for fuel equipment
After conducting treatment of the system it is advised to use Jet 100 Fuel Pump Protect Diesel product once per 6000 miles of run to prevent the high pressure fuel pump from consequences of using low-quality fuel and wear of plunger pairs.
If there is improper functioning of the engine temperature sensor, it should be changed.