SYMPTOMS VP44 PUMP FAILURE, ELECTRONIC FAILURE AND MECHANICAL FAILURE (ADVANCE)

Let’s go with the most common failure symptoms or failures of the electrical part of the VP44 pump, we are going to see the failure symptoms, from the most common to the less common ones:

1. Fault 1: The car is in motion, driving and stops suddenly
   • If you start the engine, it does not start, diesel oil comes out of the injectors without pressure.
2. Fault 2: The car starts and runs fine when cold, once warm the engine stops or jerks, once it cools down again it starts and runs fine.
   • In cold it goes all right, in some cases if the pump cools down with water it starts before, once warm again it jerks or stops, usually if with these symptoms it does not throw white smoke.

In both cases, they are problems of the electrical part of the VP44 pump, additionally we can see the most common fault codes by brand (see below), to be on the safe side, the ideal is to connect a diagnosis and see what faults are present, we can also check the fuse and the wiring that reaches the pump connector (to be on the safe side) once this is ruled out, we can almost ensure 100% that the failure is in the electrical part of the pump.

See: VP44 pump pricing and electrical repair here.

The failures that the VP44 pump gives us in the mechanical part or advance of the pump are different, and the most common are the following:

1. Fault 1: You park the car and after a few hours (or the next morning) it does not start or it is very difficult to start, if you manage to start it, it makes a lot of white smoke.
   • This failure is due to the loss of diesel oil, we may not visibly see any loss, but if it loses pressure and air enters the fittings it will be difficult to start and it will not generate enough pressure to start.
2. Fault 2: The car starts but it sounds very loud, as if the connecting rod is biting.
   • This problem is directly related to the pump advance, i.e. it is injecting out of point, since due to mechanical failure it does not adjust the mechanical advance.
3. Failure 3: Loss of power, this, like the advance failure, is related to the mechanical part of the pump, which either does not inject enough or does it out of point, causing a loss of power.
4. Fault 4: Visible diesel leakage, in many cases the car is running well, which leaks diesel.
   • This failure is very common, and we can see it visibly, the solution? disassemble the pump, replace the O-rings, adjust it and check it on the test bench

As we can see, diagnosing a mechanical failure in a VP44 pump can be complex, the ideal is to connect a diagnostic machine and see what fault codes we are getting, in some cases there are problems in the fuel supply, so it is good practice to check this before disassembling the pump.

See: Prices and estimate to repair mechanical part of a VP44.

The VP44 pump is an electronic injection pump used in diesel engines. It is known to be used in vehicles of various brands such as Dodge, Cummins, Audi, BMW, Opel, and more. Here’s how it works:

Main components of the VP44 pump:

1. ECU (Electronic Control Unit): Controls the amount and timing of fuel injection. It is mounted directly on the pump.
2. Distributor piston: Determines to which cylinder the fuel will be sent.
3. Transfer pump: Raises the fuel to a higher pressure before it enters the distributor.
4. Pressure regulator: Maintains a constant fuel pressure on the high pressure side.
5. Solenoid valve: Controls the start and duration of fuel injection.
6. Fuel Quantity Meter (FQM): This is a solenoid controlled by the ECU that determines the amount of fuel injected.

Operation:

1. Fuel Supply: The transfer pump draws fuel from the tank and pressurizes it. This pressurized fuel serves two functions: to lubricate the pump and to be injected into the cylinders.
2. Injection control: The ECU receives information from various engine sensors and, based on this data, controls the solenoid valve and MQI to determine when to start injection and how much fuel to inject.
3. Distribution: The distributor piston rotates and, depending on its position, sends fuel to the corresponding cylinder. Fuel quantity and injection timing are controlled by the ECU.
4. Injection: Once the fuel is sent to the correct cylinder and in the right amount, it is injected at high pressure into the cylinder, which causes combustion.

Aspects to consider:

• The VP44 pump is known to be sensitive to fuel quality and pressure. A poor quality fuel supply or a defective transfer pump can reduce the life of the VP44.
• Lubrication of the pump is essential. The pump uses the diesel fuel itself for lubrication, so fuel quality is crucial.
• Common problems with the VP44 pump include ECU failure and wear due to poor lubrication or contaminated fuel.

While the VP44 pump has been widely used, it has gradually been replaced in many applications by more modern injection systems due to its limitations and known problems.

If the VP44 injector pump is out of tune, i.e. not aligned correctly in terms of synchronization with the engine, it can cause a number of problems. Correct injection pump timing is essential to ensure that fuel is injected into the cylinders at the right time. Here are the most common consequences and problems if the VP44 is out of tune:

1. Starting Problems: The vehicle may have difficulty starting or may not start at all.
2. Poor Performance: There may be a noticeable loss of power and acceleration. The motor may run erratically or jerk.
3. High Fuel Consumption: Poor injection timing can lead to inefficient combustion, which in turn can increase fuel consumption.
4. Increased Emissions: Inefficient combustion can also result in increased exhaust emissions. This can lead to a stronger exhaust odor and, in some places, problems with vehicle emissions inspections.
5. Abnormal Noise: A “knocking” or “clunking” noise may be audible, especially during acceleration. This sound is the result of premature or delayed combustion.
6. Overheating: Incorrect timing can cause an increase in motor temperature, which could lead to long-term damage.
7. Engine Damage: If the pump is significantly out of tune, fuel may be injected at a time when the valve is open, which could cause engine damage due to excessive pressure.
8. Accelerated Wear: Improper injection can also result in accelerated wear of engine parts, shortening engine life.

If you suspect that your VP44 injector pump is out of tune or experience any of the above symptoms, it is crucial that you seek the diagnosis and intervention of a diesel mechanic. Operating a vehicle with an out-of-sync pump can result in costly damage and significantly reduce engine life.

The replacement of a VP44 injector pump generally takes between one and two hours. However, the time may vary depending on the vehicle model. For example, on vehicles such as an Opel VP44 or a VP44 mounted on a BMW, the process is faster, while on a Nissan it may take longer.

It should be noted that these times are approximate and may vary depending on factors such as the mechanic’s experience, working conditions and the availability of suitable tools.

The VP44 injector pump, widely used in many diesel vehicles, can experience failures in both its electrical and mechanical parts.

Electrical failure:

1. The car stops suddenly and will not start; diesel fuel comes out of the injectors without pressure.
2. The car starts and runs well when cold, but once warm it jerks or stalls. In general, it does not emit white smoke with these symptoms.

Mechanical failure:

1. The car does not start or has a hard time starting after being parked for a while and emits a lot of white smoke.
2. The engine sounds loud, as if there is a problem with the connecting rod, indicating a problem with the pump advance.
3. There is loss of power due to insufficient or off-point injection.
4. Visible loss of diesel fuel.

It is essential to connect a diagnostic machine to identify specific error codes, although fuel delivery problems should also be considered before disassembling the pump.

The time to change a VP44 injector pump is generally 1-2 hours, varying according to the vehicle model.

If you suspect a problem with your VP44 pump, it is recommended that you seek diagnosis and intervention from a diesel engine specialist.