D6NN9A543G | Genuine Ford® Fuel Injection Pump For Ford 3 Cylinder

1. To pressurize the fuel

Engines—especially diesel—need fuel at very high pressure so it can be sprayed (atomized) into the combustion chamber.

2. To deliver the correct amount of fuel

The pump measures and sends exactly how much fuel each cylinder needs based on load, acceleration, and engine speed.

3. To control injection timing

It ensures fuel is injected at the precise moment in the engine's cycle. Correct timing affects:

• Power

• Efficiency

• Engine smoothness

• Emissions

4. To distribute fuel to the injectors

In many systems, the pump sends fuel to each injector in sequence, matching the engine’s firing order.

5. To ensure efficient combustion

Proper pressure, timing, and quantity result in:

• Better fuel economy

• More power

• Cleaner exhaust

• Reduced engine noise

1. Hard starting or no start

If the pump can’t build enough pressure, the engine will crank for a long time or fail to start.

2. Loss of power / poor acceleration

Low fuel pressure from a worn pump causes:

• Weak acceleration

• Poor pulling power

• Struggling on hills

3. Rough idle or engine misfires

Uneven fuel delivery makes the engine shake, idle roughly, or misfire.

4. Excessive smoke from the exhaust

Different smoke types can give clues:

• Black smoke: too much fuel (over-fueling)

• White smoke: unburnt fuel (low pressure or bad timing)

• Blue smoke: oil burning (not always pump-related but can be connected)

5. Sudden engine stalling

If the pump can’t keep consistent pressure, the engine may stall while driving or idling.

6. Poor fuel economy

Bad fuel metering from the pump causes the engine to use more fuel than normal.

7. Engine overheating

A weak pump can cause the air-fuel mixture to run lean, increasing engine temperature.

8. Fuel leaks

A cracked or worn pump housing can leak diesel, leading to:

• Smell of fuel

• Visible wet spots

• Low fuel pressure

9. Unusual noises from the pump

Grinding, whining, or ticking sounds can indicate internal pump wear or failure.