Bosch VP44 - Bosch VP44 high pressure pump failures

Bosch VP44

Bosch VP44

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.


  • Dragan Kostic says:

    I read on the net thousands of articles on repairs and repairs of the bosch pump model VP44-psg16 and just reading the text from your site I feel you are dealing with a problem. My question is about the pump on my vehicle saab 9.5 2.2 from 2004. car, exceptionally and I have no problem but my thinking and attitude is a little unusual so I would like to have one pump or better yet just an electronic part always with me in the reserve and the reason is very simple. My wife got sick and we often go far from Belgrade looking for medicine and I'm afraid that the car won't stop somewhere. How much would it cost?

  • Norman says:

    He showed me the error that the sensor was gone, and such a sensor I can not buy here nobody will sell the sensor, or if there is a demand for it from 100 to 200 € almost half the pump and for the pump they ask for 500 € and that for zafira 2003
    Can you help me where such a sensor can be bought here in serbia but thanks from the spare parts store thanks in advance

  • Stefan says:

    Respected I have a problem with the car (Opel Zafira 2.0dti, pump vp 44) and everyone tells me that the bosch pump is in question, namely the failure is as follows: start without problems whether it is cold or hot without any problems, goes normally to the maximum speed predicted at the factory, the only problem is when it warms up at operating temperature there is uneven ler gas, I feel like the rpm varies by 50rmp of course on the index finger it doesn't notice. Did you have a problem with the pump and is it serious? hall in advance on the answer

  • Milan says:

    Dear Sir, I have a problem with the audio 4 2,5 tdi.I did almost electronics of the bosh pump. The other day it started to work harder, but now no way. I can start it with a start spray and then it only works for about 10 minutes. when it is off for 10 min again with only the start spray. thanks for the reply

  • dragan says:

    i have a problem with opel zafir 2.0dti 2001 whatever the car will not start the first ignition is a problem i have to pump the fuel with the pump installed when it lights up all day it fires without problems only if it's very cold after 3 hours of standing again i have to pump and i see that i increased the spending thanks too

  • Sase says:

    Hello.My bmw 320d 1999 sometimes trokes sometimes not. I didn't change the electronic nozzle, but it's not the same again. It doesn't matter if it's cold or poplar, or whether it's low gas or more, it can be a super three to spend three days. It doesn't show anything on the computer.

  • Nile says:

    Greetings. I have a problem with a BMW e46 320d, 100KW, 2001. It switched off at about 4000 rpm.
    Until then, I had no problems, except mandatory maintenance, oil, filters, etc. The car has crossed 235 km.
    The reason why it failed was the Bosch vp44 pump. I then found that it was not pushing oil onto the injectors. I repaired the B.pumps, mounted the man on my car, but immediately on the ride I noticed that the car was quite sluggish especially in the first and second gears until the turbine came on. Diagnosis in another human is indicated by an error-magnetic needle. The repaired man persistently claims that he did the work and that it should be so. I have been a car for almost 8 years, so I know how he behaved. If your opinion can?

    With respect, thank you.

  • Biljana says:

    Dear, I have a problem with the passat b5, 1,9 diesel, 81 kw, when it is not driving without trouble it lights up, though it exudes thick white smoke from the beginning, and when it reaches operating temperature even after extinguishing, after a short time when I want to I turn it on, it won't. For a long time it does not receive gas. It happened on the ride, after the brake was pressed to switch off or when gas was not constantly added? Thank you!

  • vanya says:

    i have a problem with the ford focus 1800tddi 2002 it crashed while driving a vergl but it does not start tomorrow day it lights up for 10 minutes i pull the master i bring bare pump 200e and while normally in the morning it crashes hard when i turn it cusa downwards fell like a mine ate who had this problem what to do

  • wax says:

    hello i have a mondea caravan 98 yr 1,8 66kw endura engine auto vergla but i can't start it and if i can start it in a few seconds and it goes off as if i didn't pull the fuel out of the tank i inspected the float and all the hoses everything is clean no clogged pump we tried infusing it and it works when I connect it to the tank it won't just eject the battery if it could be up to the electronics the pump is luxas

  • Aleksandar says:

    Please do you have a contact phone… thank you… and where are you .. and can I pick up a pump or have someone bring it ..thanks… do you also work with injectors .. the work in question is the Audi A6 v6 2002 2.5tdi 155hp… 114kw multitronic ime namely the car dugoooo vergla I will not ignite with a little spray spray pilot ignites and hot starts without problems goes nicely… but cold night without spray night… and in an instant expels white smoke… a few seconds and then normal totally works… otherwise the car has crossed 280 thousand but it was maintained super… thanks

  • Nikola says:

    I have a problem on the 2.5 120 kw audible and trok, then it stops sometimes goes smoothly sometimes and in trok rides I went to visit no one knows what may be suspected of electronics on the bosh pump but nothing is true. If someone knows thank you

  • Vlada says:

    I have a Opel Corsa 1.7dti vergla long and hard to ignite, put all the fuel back into the tank.
    It does not show any error in the diagnostics, I put a non-return valve on the inlet hose and after that it still works harder.
    Have you had a similar problem, as my masters are pushing for some tell-tale electronics bare pumps, others pumping, third again something else, and I don't know where to go.
    If you can help me, thanks in advance.

  • Dear I have a problem with the Opel Zafira 20 dti 2001. When leaving, the car suddenly stopped and stopped and only the wagon will not start, the master says that the problem is the bare pump what to do. Thanks in advance.

  • Milan says:

    Ford Transit 2.4 92kw traveled 128000km 2005god vergla never to work that it could be a pump defect or some minor malfunction… thanks who knows how to help

Leave a reply