|Trouble Code||Fault Location||Probable Cause|
|P0087||Fuel rail/system pressure too low||Fuel pump, fuel pressure regulator, fuel supply pipe blockage, mechanical fault|
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What Does Code P0087 Mean?
Well-known on diesel engines, high-pressure fuel injection systems have made their way to gasoline engines, specifically those equipped with direct injection systems. Direct injection, unlike port injection, injects fuel directly into the cylinder and, depending on driver demand, may inject fuel during the intake stroke or near the end of the compression stroke, or even during the power stroke. To make such injection possible, particularly when injecting at the end of compression or during the power stroke, high pressure is required, and the typical high-pressure fuel injection system usually runs from 200 psi to over 3,000 psi, whereas common port fuel-injection systems usually run between just 10 psi and 65 psi.
Direct fuel injection systems may or may not be paired with port fuel injection systems, but one thing they all share is the presence of two fuel pumps. Usually located in the fuel tank, an electric low-pressure fuel pump sends fuel to the high-pressure fuel pump, which is mounted on the engine. The high-pressure fuel pump is mechanically-driven, usually by a special camshaft lobe, boosting fuel pressure to over 200 psi, depending on driver demand and ECM command of the pressure-regulating spill control valve.
The engine control module (ECM), in addition to controlling fuel injection, monitors fuel pressure in the system, which it uses to fine-tune injector pulse-width. If the ECM detects that fuel pressure isn’t rising sufficiently on command, it will set a diagnostic trouble code, DTC P0087, “Fuel Rail/System Pressure – Too Low,” and illuminate the malfunction indicator lamp (MIL). Concurrent DTCs may include cylinder misfire, air-fuel ratio sensor, or fuel trim codes.
What are the common causes of code P0087 ?
Depending on year, make, and model, DTC P0087 may have number of causes. Here are some of the most common.
- High Mileage Vehicles or Bad Fuel – Fuel filters are designed to catch only a certain amount of contamination. Once they fill up, they practically block all fuel flow. In spite of fuel purity standards, contamination can build up over time, or experienced on at least few occasions, a bad batch of super-contaminated fuel can clog up a fuel filter in just a few minutes.
- 2001-2004 General Motors – Some of these diesel-powered vehicles suffered from collapsed or kinked fuel line problems, restricting fuel flow to the high-pressure fuel pump. Additionally, new fuel injectors were prescribed to address this problem. (Chevrolet Silverado, Kodiak C4500/C5500; GMC Sierra, Topkick C4500/C5500)
- 2005-2007 Volkswagen – Some high-pressure fuel pump cam followers failed, leading to low fuel pressure problems. In most cases, the cam follower would turn concave, sometimes blowing off the face and damaging the camshaft and the fuel pump. Most vehicles simply required a new cam follower, though some required a new camshaft. Rarely, the fuel pump plunger was affected, requiring replacement of the fuel pump. (Volkswagen Eos, GTI, Jetta, Passat)
What are the symptoms of code P0087 ?
Aside from the MIL, you may note rough running, engine misfires, and poor acceleration. Some vehicles, those equipped with both port- and direct-injection systems may run “fine,” up to a certain point, but will suffer poor fuel economy. Depending on the severity of the problem, some vehicles may experience hard starting or may not start at all.
How do you troubleshoot code P0087 ?
Typically, a fuel pressure monitor will not run unless the fuel pressure sensor monitor has run and passed. If you see a concurrent fuel pressure sensor or circuit DTC, diagnose and repair it first. Then turn your attention to fuel pressure itself.
- Did you run out of fuel? If you run out of fuel, there won’t be enough fuel in the lines to pressurize, resulting in this DTC. Clearing the DTC and adding a fresh tank of fuel will fix this in no time.
- Check for fuel leaks. Obvious fuel leaks, where you can see dripping or can smell raw fuel, will not allow pressure to build properly, leading to a low-pressure condition. Repair as needed.
- Check the fuel lines for kinks, which would obstruct fuel flow and prevent pressurization. Some plastic fuel lines are especially prone to kinking and collapse, obstructing fuel flow from the low-pressure pump to the high-pressure pump.
- Check the fuel filter for contamination, particularly on high-mileage vehicles, which can also obstruct fuel flow.
- Check the fuel tank for damage. External fuel tank damage could impact the fuel sender inside the tank, leading to poor fuel intake by the low-pressure fuel pump.
At this point, you may not be able to perform any further diagnosis, as the high-pressure fuel system requires special tools and procedures.
Codes Related to P0087
- DTC P0088 Fuel Rail/System Pressure – Too High
- DTC P0089 Fuel Pressure Regulator 1 Performance
- DTC P0090 Fuel Pressure Regulator 1 Control Circuit
- DTC P0091 Fuel Pressure Regulator 1 Control Circuit Low
- DTC P0092 Fuel Pressure Regulator 1 Control Circuit High
- DTC P0093 Fuel System Leak Detected – Large Leak
- DTC P0094 Fuel System Leak Detected – Small Leak
BAT Team Discussions for P0087
- 2012 Kia Optima hard start
I suggest a proper diagnosis before you spend anything throwing parts at it. If your scan tool will not communicate, find one that will. Check ALL fuses. If you think fuel might be an issue, check fuel pressure. Open the hood and do a physical inspection. Make sure you have sufficient voltage. I'...