P0087 Fuel Rail/System Pressure Too Low
Fuel pressure at the rail is below what the computer commanded — the engine is being starved, and it will get worse under load.
Fuel & air
The ECU commands a rail pressure and measures the result through the fuel rail pressure sensor. P0087 means measured pressure fell meaningfully short of commanded. On modern direct-injection and diesel systems the pressures involved are very high, and the ECU will cut power to protect components rather than let the engine run starved.
Diagnose P0087 on your specific vehicle Add your year, make and model for ranked causes, repair videos and the exact parts you needCan I keep driving?
Driveable
Not far, and not confidently. Loss of power under load is the warning before a stall. On a diesel with suspected pump failure, stop driving and get it diagnosed before contamination spreads.
How serious
High. This commonly progresses to a no-start or a roadside stall, and on diesel systems a failing high-pressure pump can shed metal through the entire fuel system — a repair that runs into thousands.
Symptoms you'll notice
- Loss of power under acceleration or when towing
- Hesitation, surging, or the engine going into reduced-power mode
- Long cranking or a no-start
- Stalling under load
- Rough idle
What causes P0087
Ordered by what to check first — how likely each cause is, weighed against what it costs to rule out. Working down the list in order is what stops you replacing an expensive part to fix a cheap problem.
Clogged fuel filter
Check this first — it is the cheapest, the most common on higher-mileage vehicles, and on many diesels it's routine maintenance that gets skipped. A restricted filter starves the high-pressure pump.
Failing fuel pump
A worn lift pump or high-pressure pump can't make commanded pressure, typically failing under load first while idling fine.
Leaking fuel injector
An injector that won't seal bleeds rail pressure away. Injector return-flow testing identifies which one.
Faulty fuel pressure regulator or control valve
A regulator stuck open, or a pressure control valve that has failed, dumps pressure back to the tank.
Restricted or leaking fuel lines
Crimped, corroded or leaking lines, and on diesels air drawn in through a loose fitting on the suction side.
Failed fuel rail pressure sensor
Worth ruling out before condemning a pump: a sensor reading low makes correct pressure look inadequate. Confirm with a mechanical gauge rather than trusting the sensor that set the code.
How to diagnose it
- Check the fuel filter's service history and replace it if it's due or unknown.
- Measure actual rail pressure with a mechanical gauge and compare against both spec and what the scan tool reports — a disagreement points at the sensor.
- Compare commanded against actual rail pressure on live data while raising load.
- Inspect fuel lines for leaks, kinks and corrosion, and check for air in the lines on diesels.
- Run an injector return-flow test to find an injector bleeding pressure off.
- On a diesel, check the fuel filter and tank for metal debris before replacing the pump — debris means the whole system needs attention.
Parts you might need
Tools for the job
- Mechanical fuel pressure gauge
- OBD-II scanner with live data
- Line wrenches
Related trouble codes
Get the parts list for your vehicle Ranked causes, tutorials and live part prices for your exact year, make and modelFitment matters. Causes and parts above are the common cases for P0087 across vehicles. The specific part numbers, procedures and torque specs vary by year, make, model and engine — always confirm against service data for your vehicle before buying parts or starting work.