Below is some information I have collected from various sources and by no means is it an exhaustive list of causes/solutions for P0087. Personally, I think that the heat in the fuel is the cause of the problem, but what to do about it is unknown. I have never read of anyone who measured the fuel temperature when the Poo87 occurred, so don't know what 'hot' really means or if that is consistently a factor in the problem.
It is noted that no one with an LML is complaining of P0087 - so there may be something of a hint at the cause that does not occur with the new trucks, but what it is, I don't know.
Problems associated with P0087 – low fuel rail pressure, usually while pulling loads, usually when hot.
Conditions for Setting the DTC
P0087
The actual FRP is more than 15 MPa (2,176 psi) below the desired FRP. OR
The actual FRP is less than 22.5 MPa (3,263 psi).
Water or gasoline contamination of the fuel may cause this DTC to intermittently set.
When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank.
When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely affect the fuel system components.
If the fuel pressure relief valve is not torqued correctly, the valve will leak fuel into the fuel return system causing this DTC to set. The fuel pressure relief valve uses a bite type seal, and proper torque is essential for valve to rail sealing. Refer to Fastener Tightening Specifications.
High fuel injector return flow may cause this DTC to set.
The addition of fuel system enhancements, such as auxiliary fuel tanks or add on fuel filters may relate to driveability complaints.
Important: If the fuel temperature is near 121°C (250°F) during the duplication of the complaint, or in the Failure Records for this DTC, inspect for a restriction in the fuel cooler air flow or the fuel heater always ON.
Circuit/System Description
The fuel filter/heater element housing consists of a water separator, a hand prime pump, fuel heater element and a filter element. Fuel passes through the fuel heater, which is operated by a built-in thermostatic switch. The thermostatic switch opens or closes to turn the heater ON or OFF, depending on temperature. Fuel then passes through the filter and the water coalescer, where the droplets of water in the fuel combine into larger drops that fall into the water reservoir in the filter. When fuel flows to the fuel injection pump, the fuel is clean and free of water.
Circuit/System Testing
Check the Water in Fuel lamp for proper operation. Refer to Water-in-Fuel Lamp Always On. See: Computers and Control Systems\Testing and Inspection\Component Tests and General Diagnostics\Water-in-Fuel Lamp Always On
1. Turn ON the ignition, with the engine OFF.
2. Disconnect the fuel heater connector.
3. With the fuel temperature above 21°C (70°F), test for continuity between the ignition 1 voltage terminal and the fuel filter/heater element housing.
If continuity was present, the thermostatic switch is stuck ON. Replace the fuel heater element.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Other solutions/information:
Collapsed fuel lines near the transmission – replace the lines
Collapsed fuel lines near the engine on drivers side near the PCV connector – replace the lines
hot fuel – could be the heater is heating all the time, not just when it needs heat.
hot fuel – could be that the fuel returning to the tank isn't being sufficiently cooled by the fuel cooler which is located under the truck just in front of the fuel tank. It can become clogged with mud and other road debris. Wash it out with a garden hose or at the car wash.
Leaking fuel head – the fuel head could have a leak in it at the o-ring, or the fuel filter might not be properly sealed, or the water sensor on the bottom may be leaking vacuum.
Leaking injectors – if the injectors leak too much (return too much fuel to the tank) this can cause the fuel pressure to be too low in the fuel rail. Only fix is to identify the offending injectors and replace them. i.e. 7 injectors may reutrn 2 and one returns 9, replace the one returning 9.
CP3 could be working incorrectly – not producing enough pressure
FPRV may be releasing pressure prematurely – not holding enough pressure
Fuel tank restriction – one person reported that the fuel pickup line was restricted with foreign material in the fuel tank. Removing the debris solved his problem.
One report said it was a dirty MAF. Cleaned with cleaner and problem solved.
Another possible problem that I have run into a few times is people who live on or drive on loose rock roads alot. I have found damage to the return fuel cooler in front of the fuel tank. It can get pin holes in the core from the rocks flying off of the tires. There is also a TSB about the 1/2" supply hose coming from the tank to the steel fuel line above the fuel cooler. Older models had a rubber hose where the new ones have a plastic hose.
My fuel line was pinched before the filter base and a o ring must have been junk on the filter base so it was sucking air in when the lines kinked off when it got hot under the hood with a large load behind the truck. New fuel lines and filter base and it has been good for 20k miles now....
