1821233C91 | Genuine International® Low Pressure Fuel Pump

1. Fuel Delivery from Tank

Moves fuel from the fuel tank to:
The high-pressure fuel pump (in common rail or HEUI systems)
Or directly to the injectors (in simpler systems)
Overcomes distance and gravity, especially in large vehicles.

2. Priming the Fuel System

Helps fill the fuel lines and filters with fuel before the engine starts.
Ensures quick starting, especially after a filter change or empty tank.

3. Maintains Proper Fuel Volume

Keeps a consistent supply of fuel to prevent:
Starvation at high RPM or heavy load
Air bubbles entering the system

4. Supports High-Pressure Fuel Systems

In diesel engines with common rail or HEUI systems:
The low-pressure pump feeds fuel to the high-pressure pump (e.g., CP3, HPOP)
Ensures high-pressure components aren't starved

5. Improves Engine Performance & Efficiency

Prevents misfiring, hesitation, or stalling
Ensures optimal combustion, fuel economy, and emissions control

Engine cranks for a long time or won’t start at all, especially after sitting or changing fuel filters.
Happens because the pump can't prime the fuel system.

2. Loss of Power / Poor Acceleration

Engine struggles when under load, going uphill, or at highway speeds.
Feels like fuel starvation.

3. Low Fuel Pressure Readings

If monitored with a gauge or scan tool, fuel pressure is:
Below spec (e.g., <10 PSI for diesel)
Unstable or drops under throttle

4. Check Engine Light or Codes

You may get fault codes like:
P0087 – Fuel Rail/System Pressure Too Low
P0093 – Fuel System Leak (Large)
SPN 94 FMI 17 or 18 – Low fuel pressure (common in diesel engines)

5. Unusual Noises from Fuel Tank Area

A whining, buzzing, or clicking sound from the fuel tank (or near the pump) can indicate:
The pump is struggling
Or drawing in air

6. Rough Idle or Stalling

Engine runs rough or stalls, especially at idle or low RPM.
Can intermittently start and die, as fuel flow cuts out.

7. Engine Misfires or Surging

Unstable or inconsistent fuel delivery leads to:
Misfiring
Hesitation
Sudden surging forward or bogging down

8. Air in Fuel Lines / Bubbles

Visible air bubbles in the fuel system or frequent need for manual priming may point to a leaking or failing pump.

9. Repeated Regen Failures (Diesel)

In diesel applications, failed DPF regens may occur if not enough fuel is delivered for injection events.