I am at 194k miles with my LR2 2008. Recently i have started receiving P0087 code and check engine light. Car runs fine and the Torque ODB2 app shows fuel pressure consistently at ~50 psi during idle and running condition. The fuel pressure drops very rapidly to zero after shutdown.

I do not want to replace the check valve (with the fuel pump), as it is a pain. The fuel sensor is original. Also the pump and the entire fuel system including filter is original.

Recent key repairs on the engine were replacement of purge canister valve (180k miles) and positive crankcase ventilation valve (PCV at 190k miles)

 

There are four variants of P0087, -00, -21, -22 and -23 but you need a scanner capable of querying Land Rover modules to see them. Or you can to go a place like Autozone and ask them to read them.

All four types have the same basic troubleshooting instructions:

• Refer to the electrical circuit diagrams and check the fuel rail pressure sensor circuit for short circuit to ground, short circuit to power, open circuit, high resistance
• Check the fuel lines for any signs of leakage, replace as required
• Check the fuel lines for any signs of damage, crimping or restrictions, replace as required
• Check for blocked air filter, replace as required

In addition, the service manual says "Check the fuel system for leaks. REFER to: Fuel Tank and Lines (310-01A Fuel Tank and Lines - I6 3.2L Petrol, Diagnosis and Testing). Rectify as necessary. Check for DTCs indicating a fuel pressure, fuel pressure sensor, pump or pump module fault."

Those DTC's are also more detailed trouble codes that require a reader that understands Land Rover modules. I would start with the simplest one, the air filter. When did you last replace it?

 

Hi flybd5, Many thanks for the prompt response. The engine air filter was replaced two weeks back and actually the code started coming after that. The filter was Mann Filter C28 155 Air Filter bought from Amazon.

Was curious how the air filter will impact fuel pressure as stated by P0087 code. Also the fuel pressure remains very steady at near 50 psi so I would assume that there is not a restriction or leak in the line.

Also, I am not seeing any lean or rich codes. I did have lean codes and misfiring codes some time back which went away after i replaced the PCV valve.

 

Did you make sure the air filter was oiled? A blocked air filter (or MAF if the filter is not working correctly because it wasn't oiled and something got through) might impact the way the car adjusts the fuel mixture, I think. Just telling you what the service manual states.

The normal fuel pressure is supposed to be 55 psi with peaks around 62 in cold start or cold fuel conditions, not the under 50 you are seeing (see chart below). That's likely why you're getting that error. If there are no other symptoms other than the code, I would replace the fuel pressure/temperature sensor on the rail.

 

Again, many thanks. My fuel pressure is definitely not there specially when off. It goes to 0 in a few seconds. Wonder why there is a difference if one is using IDS or not.I am reading pressure using ODB2 and Torque. Should it be 54 psi or should it be 68 psi.

 

It doesn't say but the way I read it the pressures with IDS are with the diagnostic system being used to turn on the pump. So normal operating pressure when not using the diagnostics system should be 54 psi.

 

Thx, so i am 4 psi less than normal.I believe it is either the fuel pump or a blockage (filter or some line). I am struggling how the sensor can be an issue.

 

It's very simple. If there are no other symptoms, it could only be the sensor is failing and reporting incorrect fuel pressure. Logic.

 

The fuel pump controller runs the fuel pump just enough to maintain the pressure.

If the sensor is bad then it will maintain the wrong pressure.

The ECU will use Fuel Trim to compensate.

Replace the sensor and report back

Thanks

Paul

 

p_gill, many thanks for the response. I will love to have the sensor go bad rather than the pump. The bosch sensor is just 50 USD and is a DIY while the pump change on this car is probably the most laborious item to replace.

Why I am questioning that the sensor is wrong because even if the sensor is faulty and underreporting, the control module should just speed up the pump to hit the desired 54 psi. The pressure is staying at 50 psi for me which means that I am at the max what the pump can achieve (either due to faulty pump or blockage) because the control module is definitely aware that the target pressure value is 54 psi and not 50 psi. So even if sensor is faulty (underreporting), the control module should be commanding the pump to speed up to hit the desired pressure of 54 psi.