Starting a diesel engine when it’s cold is different than starting it when it’s warm. Find out what is happening when you start your warmed diesel engine.
1. Starting a warmed diesel engine
Difficult start of the warmed diesel engine as opposed to the easy cold start can be caused by the high pressure fuel pump malfunction connected with the plunger pair wear. When fuel warms up, its viscosity decreases and hydraulic losses in clearances increase. In this case plunger piston cannot make enough pressure to open the injection nozzles during the engine start and fuel is not transferred to the combustion chamber.
2. Sensor malfunction
A modern diesel engine failing off the warm start may be connected with malfunction of the sensor of the operating injection nozzle. One of the engine nozzles is equipped with the engine temperature sensor. By cold start of the engine this sensor gives a command to change the injector spray angle and to warm up fuel in the filter (if the engine is equipped with such a system). If the sensor is broken, then it gives the same a command by warm start as by cold start. As a result overfueling occurs, appearance of vapour locks in fuel lines and the engine start is hard.
Here’s what you can do.
1. Check for signs of wear
In case of uncritical wear of plunger pairs of diesel engine high pressure fuel pump it is not necessary to replace the fuel pump. It is recommended to conduct fuel system flush introducing in the fuel tank one of the cleaning agents for fuel systems of diesel engines:
2. Treat the fuel system
After flushing, treat the fuel system with one of the following XADO gel Revitalizant® products for fuel systems for restoration of plunger pairs from wear:
3. Protect the fuel system after treatment
After treatment of the fuel system with XADO Revitalizant® it is strongly recommended to use Jet 100 FuelPumpProtectDiesel – Agent for protection of fuel system (Diesel) use once per 6,000 miles of run to protect the high pressure fuel pump from possible application of low-quality fuel and from future wear of plunger pairs.
4. The engine temperature sensor
If there is any malfunction of the engine temperature sensor on the operating nozzle, the sensor should be replaced.