The fuel preparation system in modern diesel engines has undergone significant changes under pressure from environmentalists. If on old engines, to start them, it was enough to turn it around with a starter, of course, if there was diesel fuel in the tank, then after the introduction of electronic control units, the start of diesel engines was significantly complicated.
Necessary
- - wrenches 10 and 17 mm,
- - electronic scanner X431.
Instructions
Step 1
When there is a problem with starting a diesel engine, it is necessary to find out the cause of the malfunction first. For the operation of these engines, it is sufficient only for diesel fuel to flow to the injectors and to the prechamber. The working mixture is ignited under pressure - a spark discharge is not needed for this.
Step 2
In older versions of engines equipped with a high pressure fuel pump (injection pump) with the number of plunger pairs corresponding to the number of cylinders, start the diagnosis by checking the low pressure line.
Step 3
Using a 10 mm wrench, unscrew the drain plug on the injection pump by a few turns. Pump the fuel into the line using a manual priming pump, at the same time, watch out which diesel fuel is squeezed out. If it comes out of the breather with a large amount of air, then this indicates that the fuel line from the tank to the pump is depressurized. It is necessary to find and eliminate the fuel leak.
Step 4
Bleed the system and remove all air from it. Tighten the drain screw on the injection pump. Try to start the engine. If the attempt is unsuccessful, then unscrew the high pressure pipe from the injector with a 17 mm wrench and turn the engine crankshaft with the starter. Diesel fuel should flow out of it under pressure. Otherwise, dismantle the injection pump and return it to the fuel operator for repair.
Step 5
With the start of diesel engines equipped with a Common Rail system, everything is much more complicated. If the engine stops starting, then first of all it is necessary to diagnose the equipment with a special electronic scanner and identify the malfunction. In order for the ECU to give a command to start the engine, it receives data from many sensors in the system. A defective device will not be able to send a signal to the command processor, and as a result, the motor will not start. In these conditions, one locksmith's tool is indispensable.
Step 6
The most common reason for failure to start a Common Rail diesel is the fuel pressure regulator valve located on the right side of the high pressure line. Unscrew the two bolts with a 10 mm wrench, replace the valve with a new part and start the engine.
