Code failures Bosch VP44 high pressure pumps can be divided:
1. Pump electronics failures that account for 60 - 70% of total failures
2. Pump mechanics failures accounting for about 25% of total failures
3. Leakage, that is, pumping defects that account for about 15% of total failures
ELECTRONIC FAULTS - high pressure pumps Bosch VP44
High-pressure pump electronics failures Bosch We find VP44 with a diagnostic device. Mostly it is a fault "Fuel level adjustment valve" means the upper valve located between the nozzle pipes. Such a broken pump does not provide fuel at the exit, so the car will not start.
On the test table, the response pump can adjust the amount and angle, when we rotate the pump we read the rpm and the temperature, but the pump does not inject fuel. The mosfet transistor is malfunctioning to drive the fuel valve. The transistor can be replaced effectively.
Another malfunction that occurs to us in practice is a CAN communication error
A pump that is broken in this way will not respond to the table, it is as if we have not connected any pump. Usually, the fuel quantity error described above is related to this error. Defective is a 5V voltage stabilizer that can be successfully replaced.
The third defect is detected by a diagnostic device (not the speed sensor) on the table, this pump responds, we can adjust the amount and angle. When we rotate the pump, it displays the temperature but does not display the rpm and does not spray the fuel. If the pump is on the car, the car will not start.
The fault is remedied by replacing the speed sensor, which is attached to the pump mechanics, and connected to the electronics by a flat cable. Flat cable and sensor need to be replaced.
It is important to note when this error occurs after about 5 minutes of operation of the car, ie. pumps on the test table.
MECHANICAL FAILURES - Bosch VP44 high pressure pumps
Malfunctions of high pressure pump mechanics Bosch VP44 can be very diverse, but in practice there is almost always a single failure. It is manifested by the car starting, not receiving gas, and it usually smokes white smoke. The diagnostic device reports an error "moment of fuel injection", and in the parameters we read the characteristic data of the mismatch of the set and realized injection angle.
The error is corrected in the following order.
We determine by visual inspection, pressure measurement, injection angle test.
We repair or replace the wrong part.
Finally, we test the correctness of the injection angle.
Clean the pump and place it on the test table.
We cut one wire from the lower valve, adjust the fuel quantity to about 2500 and rotate the pump first to 100, and gradually increase the table speed to 400 rpm.
With the stroboscope, we monitor the pump angle at about 100 rpm, the angle is zero and gradually increases to 16 degrees. If we do not have the result described in this way, we have confirmed the error.
The following test is a pressure transversal test which must be at least 9 bar at 400 rpm. We measure it on the housing on the transverse pressure measuring connector. If he does not make a mistake, he is in the fuel supply or the transverse pump (this is usually ok).
In the next measurement, remove the lower valve (to regulate the angle) and in its place to measure the transverse pressure at 400 rpm must be 9 - 18 bar .. if we do not have such pressure the fault in the pump housing is so called. the coil.
If the pressure is ok unscrew the piston cover and try running the piston with your finger. Most often the piston is stuck (made by a lynx and blocked).
After reparation, we return the pump pulley, to see if the pump regulates the angle as described above.
CHILD FAULTS - Bosch VP44 high pressure pumps
Pump breathing failures generally occur in winter. They manifest that the car will not start in the morning. After lofting, the pump switches on and works all day. It is important to inspect the return hoses of the nozzle and to determine whether it is breathing.
It is measured as follows:
We remove the hoses from the fuel supply that leads to the return of all nozzles, we make a vacuum on it, for example - 1 bar with a vacuum pump. After 15 minutes, check whether there is a vacuum. If that's ok. We take off and preheat the pump.
The pump usually does not seal on the pump locking screw (eraser), the pump electronics eraser (located under the electronics).
After repair, close all pump drains and make a vacuum at the inlet and monitor for 1 hour the vacuum is constant.
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