Stampa Chiudi
06 DIAGNOSTIC SYSTEMS EUROCARGO 77.10.10 INJECTION PUMP ASSY
Subject
Instructions for a correct diagnosis and check of the fuel feed circuit and the common rail injection system.
Description
In the "Dealer action" section the procedure is laid out for the carrying out of a diagnosis of the high pressure pump and fuel feed circuit components, on the Tector 4 and 6 cylinder engine, to prevent making unnecessary replacements.
Vehicles affected
All EuroCargo Tector vehicles.
Dealer action
Follow the procedure if the following faults are exhibited:
With fault code: 8.3 (with this fault, checks must be carried out up to point 4 of the
procedure).
Noticeable drop in engine performance (approx. 75%) accompanied by the blinking of
Service
Information
2003/0024/1
the EDC control unit warning lamp and fault code: 8.1, 8.2, 8.4;
The engine stalls (fault code: 8.5);
The engine will not start or starts with difficulty;
The engine runs erratically but no fault code is displayed.
On 4 cylinder engined Tector vehicles: if fault code: 8.1 is displayed and the engine serial number lies between 10811 and 17224 (data set for single relief valve and dual relief valve DBV2), the Field Campaign E61 procedure must be followed, refer to SIP 2001/0094/1.
Procedure
Using Modus check the value of the duty cycle at idle speed and with the engine at operating temperature; proceed as described below if the value does not lie between 1% and 5%.
1) Duty cycle
With Modus/IT2000 connect to the diagnostic socket, select - EDC7 - Parameters - Start The 'Duty Cycle' on Modus/IT2000 screen is shown as "PWM OUTPUT FOR HIGH PRESSURE PUMP"
1a) CHECKING IF THE DUTY CYCLE EXCEEDS 5% (FUEL FEED)
The following is a practical method for checking the operational condition: induce the fuel from a separate reservoir and catch the return fuel in the same reservoir.
To do this, connect a temporary feed pipe to the delivery pump and hold the other end of the pipe in a perfectly clean reservoir with clean fuel.
If, under these conditions, the duty cycle does not fall within the specified values proceed further with point 2. If the value is correct however, there is a fault in the fuel feed system and the following checks must be carried out:
Check that there is fuel in the tank Check that the tank is clean.
Check that the fuel pipes are connected properly to the tank (correct any swopped
connections). N.B.: Fault code: 8.5 of 8.1 will appear with any swopping of the pipes.
Check for blockages or leaks in the fuel pipes between:
- fuel tank and pre-filter;
- pre-filter and heat exchanger entry (control unit);
- heat exchanger (control unit) exit and mechanical delivery pump entry; - delivery pump entry and fuel filter;
- fuel filter and high pressure pump entry (CP3);
1b) CHECKING IF THE DUTY CYCLE IS BELOW 1% (FUEL RETURN)
Connect a pipe to the fuel filter so that the return fuel is caught in a separate reservoir. If, under these conditions, the duty cycle does not fall within the specified values proceed further with point 2.If however the value is now correct, there is a fault in the fuel return system and the following checks must be carried out:
Check that the fuel pipes are connected properly to the tank (correct any swopped
connections). N.B.: Fault code 8.5 will appear when reading out using the fault code button (fault code 8.1 when reading out using Modus) with any swopping of the pipes.
Check the return pipes (from the cylinder head, from the relief valve (DBV) and from
the high pressure pump) at the connection to the fuel filter and the return pipe to the tank.
Check the condition of the filter elements.
2) CHECKING THE LOW PRESSURE SYSTEM
Check the delivery pump output pressure; as described below.
Connect a pressure gauge (with a scale range to 10 bar) to the pipe between the delivery pump and the fuel filter and measure the pressure at idle speed and with the engine at operating temperature.
Working correctly, the pressure should be approx. 5 bar; if the value is lower, replace the complete pump, following the instructions described under point 6 of this procedure. Following replacement, check that the duty cycle value is correct.
If the measured pressure is approx. 5 bar, proceed further with point 3.
3) CHECKING THE HIGH PRESSURE SYSTEM.
If it is certain that there are no faults in the low pressure system, checks must be carried out on the high pressure system.
If fault code 8.4 is shown and the relief valve (DBV) leaks, proceed with point 4. Disconnect the return pipe from the relief valve (see photo 1) and blank off the plastic
pipe. No fuel must be leaking from the valve; if that is the case, replace the valve.
Following replacement, check that the duty cycle value is correct.
If the relief valve is OK:
Check the return from the injectors from the cylinder head (at normal idle speed and
without the air compressor or airconditioning compressor in operation) as follows:
Disconnect the return pipe and blank it off (see Fig. 2). At idle speed, no more
than 40 ml of fuel per minute may flow from the connection to the cylinder head; if this quantity is correct and the duty cycle still exceeds 5%, the complete pump must be replaced, following the instructions shown under point 6 of this
procedure.
Excessive return amounts can be caused through a poor seal between an injector
and the relevant feed connection (see Fig. 3); check that the feed connections have been tightened properly.
If, following the foregoing procedures, the return quantity and the duty cycle
value are not in accordance with the specified values, check if the end of a feed connection to the injector has not been over deformed (see Fig. 3a); if this is the case it must be replaced.
Remember that after removal of the injectors, the connectors (even if they are not deformed) must be replaced.
Following completion of these procedures, re-check the return quantity and the
duty cycle value.
4) CHECKING THE ELECTRICAL CONNECTIONS.
Check the connection on the high pressure pump regulator (connection between
the wiring and connector, connector pin corrosion, see Fig. 4); fig. 2.
Fig. 3
Check that the wiring and it's connection to the control unit is OK (see Fig. 5) Check that the wiring and it's connection to the rail pressure sensor is OK (see
Fig. 6).
5) CHECKING WITH DIAGNOSTIC EQUIPMENT.
If during normal engine running the engine speed can be changed using the accelerator, the values of the "fuel pressure" and the "desired fuel pressure" [Modus parameters = FUEL PRESSURE SETPOINT] should be very similar.
Measure the base pressure value and depress the accelerator pedal fully (100%). Too great a difference will be seen by the control unit as a possible fault and will register a fault code (normally 8.1); this will need the engine to be re-calibrated.
A pressure of at least 150 bar is necessary to start the engine. This value can be read out with diagnostic equipment in the "Read out Parameters" configuration. If this value cannot be achieved, point 1 of this procedure must be repeated and the efficiency of the delivery pump checked.
6) REPLACEMENT APPROVAL.
Every high pressure pump replacement on EuroCargo vehicles must have prior approval from the Technical Help Desk for the relevant market.
Approval can only be obtained after the workshop has carried out the complete engine test procedure (check up) and has sent a copy of this test to the relevant market Technical Help
4
Desk by FAX. The replaced components must be returned as quickly as possible through the usual channels.
The costs of replacing the components not approved by the Technical Help Desk for the relevant market or without the required documentation (engine test), will not be refunded to dealers or sub-dealers.
In every case replacement cost refunds will only be made following receipt of the replaced components.
N.B.: If a customer has complaints about too low engine performance, without fault code 8.1 or 8.4 appearing, replacement of the high pressure pump is not permissible.
