N47, fuel pump problem? Cutout

[bearman68]

No. The fuel pressure default zero voltage is 0.5v. It should never be below this. When you switch the ignition on, the ECU checks this voltage, and if this is OK, it will energise the fuel flow solenoid to the fuel pump. If the self check voltage is not 0.5v, the ECU will protect the system by not allowing it to start. (ie it will starve the fuel pump of fuel and keep the fuel pressure at zero)

[PLuKE]

We added 20L of fuel, to make sure it was the fuel level/pump, cranked the car over for 15-20 bursts, while getting a jump off my friends car.

My car started, while the engine was running 0.7v, engine off and ignition on 0.3v.

Does this mean the fuel pump isn't priming? and also while the engine was on, the fuel gauge was fluctuating

Many thanks

[bearman68]

The voltages you have quoted are off. It shouldn't run at 0.7v, and it shouldn't read 0.3v on ignition. Either you have your measurements wrong, or something is up with the pressure sensor. Maybe you have a poor connection to the test probe? Don't know, but this 'aint right, and it's a fundamental sensor flaw.

[PLuKE]

It does seem odd, These E60/61 are temperamental cars.

My update again: We got the car running perfect. We left the car for 30-40mins and went back outside to check it started, it had one cough and then fired up. So seems fuel pump related. Will look further into this.

We have checked these voltages several times, so it does seem odd.

I shall report back, incase anybody else has this problem.

Luke

[PLuKE]

The car seems to be running normally now. The fuel level sensors (LH and RH) had a black residue on the contacts, so cleaned all this off and the fuel gauge is stable and reporting the correct fuel level after putting £30 diesel in. The breakdown seems to have been the result of the fuel gauge reporting 1/4 tank, but being empty in reality.

Cranking the car over got fuel back in the lines and eventually the car started, so I still have questions; shouldn't the fuel pump run and prime the system on ignition on? Because my fuel pump only comes on when engine is cranking/running. Ive had the fuel pump lifted partially outside of the tank and checked this. Also, the Fuel Rail Pressure Sensor reports 0.3v on ignition on - engine off, and 0.7v engine running. So could there still be a potential fuel pressure problem either from the fuel pump, or the FRPS giving a false reading?

[helix402]

Afraid I'm not going to try any online diagnosis for you, but why not buy a Creator C310. You can read live data, actual against specified and check all your readings are ok.

[IrealBMW]

Hi, folks.

I have this BMW 520d E60, engine N47D20A from 2007.

I had few problems after I bought it, but I sorted them out and for two years I never had major problems with the car.

Few weeks ago while driving on a 40 miles/hour the engine stopped suddenly after the “engine” sign showed on the dashboard, saying something about loss of power. I tried to start the engine, with no success.

I had Carista app so I scanned the ECU and I had the followings errors:
4560 - Rail Pressure Sensor - Plausibility - Pressure Too Low
4570 - Rail Pressure Not Plausible
4610 - Rail Pressure Not Plausibile
4B90 - Rail Pressure Control at Engine Start

I called AA and they arrived in less than 30 minutes (I was happy with the choice I made) and they scanned the ECU using a more professional tool and they had the same errors. They towed me home and since then I tried everything in order to fix it.

I checked all the fuses, all OK.
I changed the Fuel Pump Relay, no change.
I changed the Low Pressure Fuel Pump from the tank with a brand new one, no change.
I changed the fuel filter, no change.
I changed the Fuel Pressure Sensor from the fuel rail, no change.
I changed the rocker seal from the rocker cover (because it was leaking a bit in the past)

I tried to start the car using EasyStart spray, but it won’t start.

I don’t know what else can I do. I did not checked any voltages since I’m not that advanced to know what it should be and where.
I removed the air as much as I could from the fuel system.

In the last few weeks, the engine RPM was fluctuating when on idle, but quite rare without the engine to stop.

Please give me an idea what could cause this problem.

Thank you in advance!

[Elliot2000]

IrealBMW said:

Hi, folks.

I have this BMW 520d E60, engine N47D20A from 2007.

I had few problems after I bought it, but I sorted them out and for two years I never had major problems with the car.

Few weeks ago while driving on a 40 miles/hour the engine stopped suddenly after the “engine” sign showed on the dashboard, saying something about loss of power. I tried to start the engine, with no success.

I had Carista app so I scanned the ECU and I had the followings errors:
4560 - Rail Pressure Sensor - Plausibility - Pressure Too Low
4570 - Rail Pressure Not Plausible
4610 - Rail Pressure Not Plausibile
4B90 - Rail Pressure Control at Engine Start

I called AA and they arrived in less than 30 minutes (I was happy with the choice I made) and they scanned the ECU using a more professional tool and they had the same errors. They towed me home and since then I tried everything in order to fix it.

I checked all the fuses, all OK.
I changed the Fuel Pump Relay, no change.
I changed the Low Pressure Fuel Pump from the tank with a brand new one, no change.
I changed the fuel filter, no change.
I changed the Fuel Pressure Sensor from the fuel rail, no change.
I changed the rocker seal from the rocker cover (because it was leaking a bit in the past)

I tried to start the car using EasyStart spray, but it won’t start.

I don’t know what else can I do. I did not checked any voltages since I’m not that advanced to know what it should be and where.
I removed the air as much as I could from the fuel system.

In the last few weeks, the engine RPM was fluctuating when on idle, but quite rare without the engine to stop.

Please give me an idea what could cause this problem.

Thank you in advance!

Hi, when you try to start it does it spin over really quickly as if it has no compression? Just to rule out a snapped timing chain.

If that’s ok, can you read fuel pressure using carista? With just ignition on at the fuel rail you should be seeing around about 4 bar, and then when cranking it should be going up to over 200 bar quite quickly, let us know what the results are

[IrealBMW]

I took the car to a garage and they said it’s the high pressure fuel pump which makes sense because the lressure of the fuel at the fuel rail is very low. They said they’ll give me a quote in order to choose if I will fix the car with them on not. A brand new HPFP is somewhere around £600 and I don’t think it will be such a big deal to change it myself.

The question is: how can the HPFP can break down suddenly without any warnings? It’s a mechanical pump, it’s quite unusual.

[helix402]

N47 high pressure pumps are sadly known for premature failure, more frequent fuel filter changes may extend their life.

[stevepoulter]

IrealBMW said:

I took the car to a garage and they said it’s the high pressure fuel pump which makes sense because the lressure of the fuel at the fuel rail is very low. They said they’ll give me a quote in order to choose if I will fix the car with them on not. A brand new HPFP is somewhere around £600 and I don’t think it will be such a big deal to change it myself.

The question is: how can the HPFP can break down suddenly without any warnings? It’s a mechanical pump, it’s quite unusual.

Hi Mate,

I have the exact same issue on my F10 520d N47

It won't start.

Did you get it sorted in the end? If so what was the fix

[skp68]

Hi there
I also have some problems with my X3 from 2007. But I have the M57D30TÜTOP Engine instead but my guess is that the sensors operates in the same way. Bearman68 wrote how to check the pressure sensor and that is ok with my car. Is there any way to check the pressure regulator at the end of the fuel rail manifold? Using Carly for BMW and an ELM adapter the RAW fuel pressure reading goes from 1200 bars up to 4000 bar (idle to higher revings). Unfortunately I don´t have any clue if there should be any calibration factor for this numbers. I have performed a back leak test on the injectors and they are all in 4% error compared to each other. I have also changed the valve that regulates the amount of fuel on the backside of the high pressure pump. Any suggestions or is the next step to change the high pressure fuel pump?

[Elliot2000]

skp68 said:

Hi there
I also have some problems with my X3 from 2007. But I have the M57D30TÜTOP Engine instead but my guess is that the sensors operates in the same way. Bearman68 wrote how to check the pressure sensor and that is ok with my car. Is there any way to check the pressure regulator at the end of the fuel rail manifold? Using Carly for BMW and an ELM adapter the RAW fuel pressure reading goes from 1200 bars up to 4000 bar (idle to higher revings). Unfortunately I don´t have any clue if there should be any calibration factor for this numbers. I have performed a back leak test on the injectors and they are all in 4% error compared to each other. I have also changed the valve that regulates the amount of fuel on the backside of the high pressure pump. Any suggestions or is the next step to change the high pressure fuel pump?

Hi, your fuel pressure readings don’t make sense in bar, I guess it could be in kpa or it could just be 1.2 bar and 4 bar- can u check which it is, (is it saying 1200 with ignition off and 4000 with ignition on? Or when cranking it goes from 1200 to 4000?)


When u say u have done an injector back leak test, do u mean the mechanical test of measuring the amount of fuel that is coming out the leak off pipes on top of injectors or something on your laptop? If it’s the latter - I wouldn’t rely on it as I can’t see how it would measure it

There is also a volume control valve on the back of the fuel rail btw.

[skp68]

When I said I have the same problem I refferred to an earlier post. My Engine starts and my reading is 1200 bar at idle and increases while driving. When I´m running with the original file my DDE lamp comes on and the goes in to limp mode. When loading a tuning program in to the DDE the engine shuts down under load instead. Is the fuel pressure supposed to be steady no matter what the load is on the engine or it is supposed to follow the load and rpm of the engine?

[skp68]

The leak back test was performed with six 30 ml syringes connected with silicon tubes to the injectors, all tubes has the same length. The test tooked a couple of minutes to perform with both idling and reving the Engine.

The regulator at the back end of the common rail manifold is pressure regulator, the flow regulator is fitted on the back side of the pump. The flow regulator is brand new and that didn´t help me unfortunately.

[helix402]

Maybe worth starting a new thread as the two engines in question are very different.

[Elliot2000]

These engines do not run fuel pressure at 1200 bar and 4000 bar as previously stated . If it is indeed reading at that value then then u have something wrong with the fuel pressure sensor or wiring. Sensors are known to go on them engines and wiring can get damaged as it pretty folds back on it self at the plug connector. Or it might just be crap software u are using to interrogate the ecu

Yes u have a control valve on the back of the pump, but the one on the back of the rail can also cause problems and stop fuel pressure being achieved when they stick open

[bmwrider]

bearman68 said:

OK, I think the oil pressure plausibility switch is a red herring.
The problem appears to be with the fuel system.
In my experience it's unlikely the mechanical bits of the high pressure pump has failed (good news), but it does have several bits to make it work correctly.

Firstly it has a low pressure electric pump located on the underside of the car (I think). This is responsible for ensuring the HP pump has sufficient fuel. Does this start with you cycle the ignition.
Then the HP pump is controlled by an Inlet metering Valve. Essentially this switches the fuel on and off to the HP pump depending on the feedback from the fuel rail pressure sensor.
The FRPS sits at the easy end of the fuel rail on the LH side of the engine, just under the cover, It has 3 wires to it, and the central one is the feedback voltage. On ignition on engine off, this should read 0.5v, and on cranking, this should rise to 1.3v (and then the engine should start) This will tell you if you have a low or no fuel pressure problem. If it gets to 1.3v and the engine starts, or attempts to start, the reading on the FRPS will then indicate if you have a leak in the system (it will fall very quickly - possible injectors or HP Fuel Pump), or if the injectors are being inhibited by something else. (Will stay at 1.3v)
Hard to describe much more without data to be honest, but hope this helps a bit, and you can do these test with a simple multimeter.

A few weeks ago while driving (530D E60, 2009) I recently suffered from a sudden loss of power, the car went in a limp mode, followed by slowing down gradually until stand still.
While it is slowing down, it doesn't react on the gas pedal, I can send it to the emergency lane after which it comes to a standstill.
The first time he did that, I had it towed to the nearest petrol station.
I went on with the trip, a week later it happened again, while in the emergency lane, I switched everything off, closed the car off and waited for a moment, after a minute or two of waiting it started again.

Now I did the test you have suggested for the previous guy, my readings:

At stationary:
cable left: 5v
cable middle: 0.5
cable right: 0.01v

---

With the engine running:
cable left: 4.97v
cables middle: 1.26 ~ 1.31v
cable right: 0.01

Any more tips as to what to check?

[DjDubz]

So my wife's 120d N47 did all the above and cut out on a roundabout on her way home! yellow engine light came on then within seconds the car died, Now she refuses to drive it. We had it scanned and had the errors;

4560 - Rail Pressure Sensor - Plausibility - Pressure Too Low
4570 - Rail Pressure Not Plausible
4610 - Rail Pressure Not Plausibile

so we did the whole process of elimination - fuel filter replacement, injectors tested, fuel rail & Sensors changed, the next thing is the HPFP which I have been told by two BMW techs that they are 99.9% sure that because one of the symptoms are on idle needle isn't steady it will be the HPFP. I'm not 100% confident doing it myself so now it is booked in to have a new Bosh HPFP.

[shahab91]

bearman68 said:

No. The fuel pressure default zero voltage is 0.5v. It should never be below this. When you switch the ignition on, the ECU checks this voltage, and if this is OK, it will energise the fuel flow solenoid to the fuel pump. If the self check voltage is not 0.5v, the ECU will protect the system by not allowing it to start. (ie it will starve the fuel pump of fuel and keep the fuel pressure at zero)

Hi,

Could you please tell a bit more about this? I have had this issue with my car for a year now. BMW replaced the HPFP but it is still not producing enough pressure. I did a check of the pressure readings with ISTA High Pressure system is doing 100 bars instead of 300 bars. No faults are present. I have bled the system many times. Feel like it has to do something with the pressure regulator solenoid. How can I check the voltage on that?