Engine power system on a crossover Nissan Murano the second generation (Z50 body) is a complex and important unit, the health of which directly affects the dynamics of the car and its ability to start in any weather. The high-pressure fuel pump and electric fuel pump assembly operate in an aggressive environment, constantly exposed to temperature changes and mechanical loads, which eventually leads to wear.
Many owners are faced with a situation where the car starts to stall, stall while driving, or refuse to start after a long period of parking. In such cases, the problem often lies not in the ECU or sensors, but in a banal drop in pressure in the rail due to a worn impellers or clogged mesh filter gas tank. Understanding the principles of operation of the system and the ability to recognize symptoms in time will allow you to avoid expensive engine repairs or replacement of the entire fuel line.
Operating principle and design features of the Murano Z50 fuel system
By car Nissan Murano Z50 equipped with VQ35DE or VQ35HR gasoline engines, the fuel system is a closed circuit with excess fuel returned back to the tank. An electric fuel pump located directly inside the fuel tank creates the necessary pressure for operation pressure regulator and injectors. This module is integrated into a unit that also includes a fuel level sensor and intake filter.
A design feature is that the pump is cooled by the fuel itself. If the gasoline level drops too low, cooling is impaired, which can lead to overheating and premature failure of the pump motor. The pressure in the system is maintained at about 3.5–4.0 bar, which is critical for proper mixture formation and stable engine operation in all modes.
When you start the engine, you should hear a characteristic buzzing sound for a few seconds - it works electric fuel pump, creating starting pressure. If there is no sound or it is quiet and intermittent, this is the first signal of a malfunction. The system is also equipped with a pressure relief valve that prevents hoses from bursting during sudden pressure surges or engine shutdown.
Main symptoms of malfunction and pressure diagnostics
Identify the problem with the fuel pump on Nissan Murano it is possible based on a number of characteristic symptoms that are often ignored by drivers until the car stalls on the highway. The most obvious sign is difficulty starting the engine: the starter turns for a long time, but the engine does not catch, especially after parking overnight. This suggests that check valve does not hold pressure and gasoline flows back into the tank.
The second warning sign is power failure during acceleration. When you step on the gas pedal, the engine may jerk, lose power, or even stall because the pump is unable to deliver the required amount of fuel under load. Also pay attention to extraneous noises from under the rear seat: a strong hum, squeaking or grinding indicates worn bearings or destruction of the impeller.
For accurate diagnosis, it is necessary to measure the pressure in the fuel rail using a pressure gauge. The connection process is as follows: find the fitting on the fuel rail, unscrew the cap and attach the pressure gauge. Start the engine and compare the readings with the standard values. If the pressure is below 3.5 bar with the engine running, the problem is almost certainly in the pump or pressure regulator.
⚠️ Attention: Never try to measure the pressure by simply unscrewing the fitting without a pressure gauge - at a pressure of 4 bar, gasoline can splash and ignite from a spark. Use only serviceable tools and follow fire safety precautions!
- Difficult start
- Dips during acceleration
- Noise from under the seat
- The car stalls while driving
Selecting the original and high-quality analogues for replacement
When choosing a new fuel pump for Nissan Murano Z50 it is important to understand the difference between original spare parts and quality analogues. Original pump from Nissan (part number usually starts with 17040) provides maximum service life and accuracy of characteristics, but costs significantly more. However, there are trusted manufacturers on the market whose products are not inferior to the original in terms of build quality and durability.
Among the popular analogues, it is worth highlighting the brands Bosch, Denso And Delphi. These companies are suppliers of components for many automakers, including Nissan. When purchasing, be sure to check the packaging for holograms and markings, since there are a lot of fakes on the market for spare parts for crossovers. Installed counterfeit pump may fail after a couple of thousand kilometers.
It is also worth paying attention to the condition of the fuel filter and fuel level sensor when replacing the pump. Often a new pump assembly comes with a new pump, which simplifies the task. If you decide to replace just the pump, make sure you purchase strainer of a suitable size, since an old filter clogged with dirt will quickly kill even a new unit.
Below is a table with the main part numbers for various engine modifications:
| Engine model | Original article | Popular analogue | Note |
|---|---|---|---|
| VQ35DE (2003-2007) | 17040-CA000 | Bosch 0 580 454 001 | Standard flow |
| VQ35DE (2008-2010) | 17040-ZZ00A | Denso 950-0035 | Improved performance |
| VQ35HR | 17040-CA010 | Delphi CG10093 | High blood pressure |
| Complete set | 17040-CA025 | Continental 17040-CA025 | Includes level sensor |
Step-by-step instructions for replacing the fuel pump
Replacing the fuel pump with Nissan Murano Z50 is a task that can be completed independently with a minimum set of tools and free hands. Start by preparing the car: turn off the engine, open the hood and disconnect the negative terminal of the battery. This is a mandatory safety requirement, since working with the fuel system under voltage is strictly prohibited.
Next you need to remove the rear seat. On most Murano Z50 trims, the rear bench is secured with hooks and latches. Gently pull the seat up, unfasten it and move it to the side. Under the floor covering you will see a round hatch covered with a plastic cover. Unscrew the mounting bolts and remove the cover to gain access to the fuel module.
Before disconnecting the fuel hoses, be sure to relieve any remaining pressure in the system. To do this, you can unscrew the fuel pump fuse from the block (usually it is labeled as FUEL PUMP) and start the engine until it stalls. Next, unplug the pump's electrical connector and carefully disconnect the fuel lines using a special clamp remover or needle nose pliers.
☑️ Preparation for replacement
Now you can remove the pump itself. It is held in place by a retaining ring that must be carefully turned counterclockwise. Be extremely careful: the plastic clamp of the fuel level sensor is very fragile and easily breaks if moved carelessly. Lift the pump upwards, being careful not to damage the float mechanism.
⚠️ Attention: When removing the pump, monitor the position of the fuel level sensor float. If it becomes bent or broken, the dashboard readings will be incorrect and the tank will not be able to be filled to capacity without turning off the low fuel light.
Install the new pump, following the orientation marks. Make sure that the rubber seal of the hatch is in perfect condition and has no cracks, otherwise you will get a gasoline smell in the cabin. Screw the locking ring until it stops, connect the tubes and connectors. Before installing the seat, be sure to check the tightness of the connections by lightly pressing the gas pedal or turning on the ignition for 3-4 seconds.
How to check for leaks without starting the engine?
Disconnect the pump connector, turn on the ignition for 5 seconds, turn off, turn on again. Repeat 3 times. Then connect the connector and try to start it. If there is no smell of gasoline under the hatch, everything is sealed.
Preventing and extending the service life of the fuel pump
In order for a new or old pump to last as long as possible, you must follow a few simple operating rules. The most important thing is to avoid running the engine on an empty tank. As mentioned earlier, gasoline serves as a coolant for the pump motor. When the level drops below 1/4 of the tank, the pump begins to overheat, which accelerates wear on the commutator and brushes.
Regularly replacing the fuel filter is also critical. A clogged filter creates increased resistance, causing the pump to overload. On Nissan Murano The Z50 filter is built into the pump module (mesh), but if a lot of dirt has accumulated in the tank, it can quickly clog this mesh. Therefore, it is recommended to use only high-quality gasoline and periodically flush the tank when driving more than 100,000 km.
Use special additives to clean the fuel system, but do so with caution. Some harsh chemicals can damage the rubber seals or plastic pump housing. It is better to choose proven brands such as Lavr or Bardahl, and add them to the tank according to the manufacturer's instructions. This will help keep the injectors and internal pump channels clean.
Before the winter season, always top up the tank until it is full. This will not only ensure the pump operates, but will also reduce moisture condensation inside the tank, which can lead to freezing of the fuel or corrosion of pump parts.
Common repair mistakes and how to avoid them
One of the most common mistakes is trying to clean an old pump if it starts making noise. Often owners try to disassemble the unit, wash it in gasoline and install it back. This is pointless: wear of the brushes and commutator cannot be eliminated by washing, and the plastic impeller is deformed over time by fuel and loses its geometry.
Another mistake is ignoring the condition of the locking ring. When reinstalling an old pump or installing a new one, the ring may be installed crooked or twisted. This leads to the fact that the hatch does not close hermetically, and the smell of gasoline penetrates into the cabin, which is especially noticeable when the stove or air conditioner is running.
Also, many people forget to check the fuses and relays of the fuel pump before replacing the pump itself. Sometimes the problem is solved by replacing a blown fuse or relay in the unit under the hood. Check the diagram in the owner's manual: on the Nissan Murano Z50 the relay is often located in the block IPDM E/R in the engine compartment. Use a multimeter to check for voltage at the pump connector.
Replacing a fuel pump is not only installing a new part, but also checking all associated elements: filters, gaskets, electrical circuits and the condition of the tank. An integrated approach guarantees long-term operation of the system.
⚠️ Attention: If the engine is unstable after replacing the pump, check whether you have mixed up the high and low pressure pipes. Incorrect connections can result in fuel injector failure and serious engine damage.
FAQ: Frequently asked questions about the Nissan Murano Z50 fuel pump
How long does it take to replace a fuel pump on a Murano Z50?
If you have experience and the right tool, replacement takes from 45 minutes to 1.5 hours. The main difficulty lies in carefully removing the retaining ring and connecting the fuel pipes without damaging the clamps.
Is it possible to drive with a faulty fuel pump?
Strongly not recommended. The pump can fail at any time, leaving you stranded on the highway. In addition, operating the pump in overload mode can lead to its complete destruction and clogging of the entire fuel system with metal shavings.
Why is the pump noisy, but the pressure is normal?
This may indicate worn bearings or internal deformation of the impeller, which does not yet affect performance, but creates vibration. The cause may also be low-quality gasoline containing impurities that cause erosion of internal surfaces.
Do I need to change the filter along with the pump?
Yes, definitely. The old filter will restrict fuel flow, forcing the new pump to work under extreme conditions. In most cases, it is recommended to replace the entire module assembly, including the filter and level sensor.
How to reset the "Check Engine" error after replacing the pump?
After replacing and checking the engine operation, the error can be reset using the OBDII diagnostic scanner. If you don't have a scanner, you can disconnect the battery for 10-15 minutes, but this will also reset other vehicle systems.