The fuel pump does not pump on a Nissan Almera Classic: reasons and solutions

If your Nissan Almera Classic refuses to start, and from under the back seat you can’t hear the usual buzzing of the fuel pump - the problem is obvious. But don’t rush to change the entire unit: in 70% of cases, the fault lies in small things that can be fixed in 15 minutes. This article will help you figure out why. fuel pump does not pump fuel, how to check its operation without special tools and what to do if it is not the pump itself that is to blame, but the electrics or the fuel system.

We will look at all possible causes - from a banal blown fuse to wear on the electric motor brushes, and also give step-by-step instructions for diagnosis. We will pay special attention unique feature Almera Classic: on these machines, it is often not the pump itself that fails, but the fuel pump relay due to factory defective contacts. If you don't want to spend money on a car service, read on.

Signs of a fuel pump malfunction

The first symptom is that the engine does not start or stalls a few seconds after starting. But there are other “bells” that many miss:

• 🔊 No sound from under the rear seat when the ignition is turned on (the pump should hum for 2-3 seconds).
• ⚡ Jerking while walking, especially during sudden acceleration, is a sign that the pump is not working properly.
• ⛽ The smell of gasoline in the cabin - may indicate a fuel leak or overflow due to a faulty check valve.
• ⚠️ Check Engine does not always light up, but if it does, be sure to check the error codes (for example, P0171 or P0174 often associated with the fuel system).

If at least one of these signs appears, it’s time to get diagnosed. But first make sure that the problem is in the fuel pump and not in something else (for example, clogged fuel filter or faulty injectors).

⚠️ Attention: If the car stalls while driving and will not start again, DO NOT try to crank the starter for too long. This may lead to overheating of ignition coils or low battery. 2-3 attempts of 5 seconds are enough.

Checking the fuel pump fuse and relay

The most common reason for a silent pump is a blown fuse or faulty relay. B Nissan Almera Classic they are in mounting block under the hood (near the battery). Looking for a fuse F/P No. 30 on 15A and relay R17 (there is a diagram on the block cover).

How to check:

1. Open the hood and remove the mounting block cover.
2. Take out the fuse F/P No. 30 and inspect it against the light - if the thread is burnt out, replace it with a similar one (only 15A!).
3. If the fuse is intact, swap the relay R17 And R18 (fan relay). If after this the pump starts working, the relay is to blame.

If both the fuse and the relay are working, but the pump is silent, the problem is deeper. Perhaps no power to the pump connector or the unit itself has failed.

Check fuse F/P No. 30 (15A)|Swap relay R17 with R18|Make sure the relay contacts are not burnt|Check the voltage at the relay contacts (should be 12V when the ignition is on)-->

How to check the voltage at the fuel pump

If the fuse and relay are ok, the next step is checking the power supply to the pump itself. To do this you will need a multimeter or at least a 12V test lamp.

Instructions:

1. Remove the rear seat and open the fuel pump hatch (it is under the black cover, secured with 4 screws).
2. Disconnect the power supply from the pump (it is white, with 3 wires: +12V, mass And level sensor signal).
3. Turn on the ignition (do not start the car!) and measure the voltage between red (+) And black (–) wires. Must be 12V.

If there is no voltage, the problem is in the wiring (breakage, oxidation of contacts) or in engine control unit (ECU). If there is voltage, but the pump does not work, the unit itself is to blame.

⚠️ Attention: On Almera Classic Contacts in the pump connector often oxidize due to moisture ingress. Before replacing the pump be sure to clean the contacts alcohol or WD-40.

Symptom	Possible reason	Solution
The pump does not buzz, there is voltage at the connector	Pump electric motor is faulty	Replacement of fuel pump or repair (cleaning brushes)
The pump hums, but no fuel flows	The filter mesh is clogged or the impeller is worn out	Cleaning the mesh or replacing the pump
There is no voltage at the connector	Broken wiring, faulty relay or ECU	Wiring test, relay replacement, ECU diagnostics
The pump works, but the engine does not start	Fuel pressure regulator faulty	Replacing the regulator or checking the return line

Do-it-yourself cleaning of the fuel pump mesh

If the pump hums, but no fuel flows into the rails, it is most likely clogged. coarse mesh. On Almera Classic it is located right at the pump inlet and often becomes clogged with rust or dirt from the tank.

How to clean:

1. Remove the fuel pump (unscrew the clamping ring counterclockwise).
2. Carefully remove the mesh from the bottom of the pump (it is held on by latches).
3. Wash it in gasoline or carburetor cleaner, then blow it with compressed air.
4. Check the condition of the O-ring - if it is hardened, replace it.

If the mesh is in order, but fuel still does not flow, the problem may be worn impeller or jammed rotor electric motor. In this case, the pump must be replaced.

What happens if you don't clean the mesh?

If you ignore a clogged mesh, this will lead to:

- Accelerated wear of the fuel pump (it works with overload).

- Fuel overheating in the tank (may cause vapor lock).

- Clogged injectors small particles of dirt.

- Pressure drop in the fuel rail and unstable engine operation.

Replacing the fuel pump on a Nissan Almera Classic

If the pump cannot be repaired, it must be replaced. For Almera Classic original pumps fit Nissan 17040-9M000 or analogues from Bosch (article 0 580 454 035). The average price is 3,500–5,000 rubles.

Step by step replacement:

1. Relieve pressure in the fuel system (pull the pump fuse and start the car until it stalls).
2. Remove the rear seat and unscrew the fuel pump flap.
3. Disconnect the power supply and fuel hoses (remember their location!).
4. Unscrew the pressure ring (you may need a puller or a hammer with a wooden spacer).
5. Take out the pump, remove the fuel level sensor float from it and transfer it to a new one.
6. Install the new pump in reverse order, remembering to replace the O-ring.

After replacement be sure to check the tightness: start the engine and inspect the pump installation site for gasoline leaks.

Additional reasons: why the pump does not pump

If you have checked all of the above and the problem remains, pay attention to:

• 🔌 Mass oxidation on the body under the pump (clean with sandpaper and process Liqui Moly Kontakt-Spray).
• 🛢️ Clogged fuel line (blow out the tubes with compressed air).
• 🔧 Faulty crankshaft position sensor (the engine will not start even with the pump running).
• 💻 ECU firmware failure (occurs after unsuccessful chip tuning).

On Almera Classic with a mileage of more than 150,000 km it often wears out fine fuel filter (located under the bottom, with the gas tank). Replacing it can restore the pump to functionality.

FAQ: Frequently asked questions about the Nissan Almera Classic fuel pump

Is it possible to drive if the pump works intermittently?

No. If the pump begins to “howl” or the engine jerks at high speeds, this is a sign of an imminent breakdown. Driving for a long time in this mode will lead to pump overheating and its final failure, and can also damage the injectors due to unstable fuel pressure.

How long does the fuel pump last on Almera Classic?

Average service life of the original pump - 100,000–150,000 km. But if you refuel at dubious gas stations or ignore replacing the fuel filter, the pump may break down after 60,000 km. Record holders among analogues - pumps Bosch And Denso, which with careful operation last up to 200,000 km.

Why doesn't the pump pump after replacement?

Probable reasons:

• The hoses are connected incorrectly (supply and return are mixed up).
• The pressure in the system was not released before replacement (air lock).
• The relay or fuse is faulty (even if it appears intact).
• Poor contact on the pump connector (oxidation or incomplete latching).

Check everything in order, starting with the simplest.

Can the fuel pump be repaired or is it just a replacement?

Repair is possible if the problem is:

• Dirty mesh (cleaning).
• Worn electric motor brushes (replacement).
• Oxidized contacts (cleaning).

If the motor burns out or the impeller is damaged, replace it only. The cost of repair is often comparable to the price of a new pump, so it is not economically feasible.

What pressure should be in the fuel rail?

For Nissan Almera Classic with engines QG15DE And QG18DE normal indicators:

• Idling: 3.0–3.5 bar.
• When releasing gas: up to 4 bar (must rise).
• After turning off the ignition: the pressure should fall slowly (if it resets instantly, the regulator or check valve is faulty).

Checked with a pressure gauge connected to the fitting on the fuel rail (you need an adapter for a quick connection).