Fuel Rail/System Pressure - Too Low
P0087 indicates the fuel rail pressure is lower than the PCM expected, meaning insufficient fuel is reaching the engine. This causes the engine computer to struggle maintaining proper fuel delivery, leading to lean running conditions, poor performance, and increased emissions.
What You Might Notice
- Check engine light illuminated
- Vehicle runs rough or misfires
- Lack of power during acceleration, especially at higher RPMs
- Poor fuel economy
- Hesitation or stumbling on throttle apply
Most Common Causes
- 1
Weak or failing fuel pump
The fuel pump cannot generate sufficient pressure to maintain proper rail pressure. This is the most common cause and typically worsens with age and mileage.
- 2
Clogged fuel filter or screen
A restricted fuel filter blocks flow and causes pressure drop in the fuel system. A clogged pickup screen in the tank has the same effect.
- 3
Faulty fuel pressure sensor
A defective pressure sensor sends incorrect readings to the PCM, causing it to believe pressure is low when it may actually be normal. This triggers the code without actual fuel pressure issues.
- 4
Restricted fuel supply line or regulator malfunction
Kinked, clogged, or damaged fuel lines restrict flow, or a faulty fuel pressure regulator fails to maintain correct system pressure.
How to Diagnose It
- 1
Check Weak or failing fuel pump — The fuel pump cannot generate sufficient pressure to maintain proper rail pressure. This is the most common cause and typically worsens with age and mileage.
- 2
Check Clogged fuel filter or screen — A restricted fuel filter blocks flow and causes pressure drop in the fuel system. A clogged pickup screen in the tank has the same effect.
- 3
Check Faulty fuel pressure sensor — A defective pressure sensor sends incorrect readings to the PCM, causing it to believe pressure is low when it may actually be normal. This triggers the code without actual fuel pressure issues.
- 4
Check Restricted fuel supply line or regulator malfunction — Kinked, clogged, or damaged fuel lines restrict flow, or a faulty fuel pressure regulator fails to maintain correct system pressure.
How to Fix It
- 1
Replace fuel filter
Remove and inspect the fuel filter for contamination or blockage. Replace with a new OEM or quality aftermarket filter and reset the code to verify the fix.
- 2
Test and replace fuel pump
Use a fuel pressure gauge to measure actual system pressure at the rail. If pressure is below specification (typically 50-60 PSI depending on vehicle), replace the fuel pump assembly.
- 3
Replace fuel pressure sensor
Disconnect the fuel pressure sensor connector and test its resistance and output voltage with a multimeter. If readings are out of spec, replace the sensor with an OEM part.
- 4
Inspect fuel lines and regulator
Visually inspect all fuel supply lines for kinks, cracks, or damage. Check fuel pressure regulator operation and fuel dampener condition. Replace any damaged components and verify pressure readings return to normal.
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