2012 V8 Gas LR4 P0087 Low Fuel Rail Pressure Sensor Problem

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VinnyAllenMX

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My wife went on a road trip and got the restricted performance warning, said the electronics started acting up and doing weird displays. Checked the codes when she got back and got he P0087 low fuel rail pressure code. Tested the fuel pressure on the rail with a guage and it was reading 60-70 psi and pressure was holding pretty good after shutting off the engine. When the engine starts cold it takes some cranking to get started and will surge, but when it warms up will idle good. Tried installing a new pressure sensor LR044707, didn't work. Tried cleaning the injectors and MAP sensors to no avail. Bought another tester so I could give live data and discovered that the gauge pressure on the rail was reading higher than the absolute fuel rail pressure being sent to the OBD monitor by at least 10 psi and about 15 psi when engine was not running. So I tried installing another LR012280 fuel sensor with pigtail permanently attached. Still the OBD monitor is reading lower by 10-15 psi what is showing on the pressure gauge attached to the rail. I believe that the proper pressure is about 65 psi, which is what is showing on the gauge. Can anyone help me here? I'm at a loss for what to do next.

Below is some of the freeze frame data for the P0087 code on the last run:

Abslt TPS(%) 16.5
Eng Speed 1159
Baro Press 29.2
Calc Load 21.6%
MAF lb/m 1.24
MAP HG 8.0
IGN ADV 45 degrees
ST FTRM2 13.3%
LT FTRm1 -2.3%
LT FTRM2 -3.9%
ST SEC FT1 0%
ST SEC FT2 0%
LT SEC FT1 -0.8%
ABS Load 16.5%
Fuel SYS 1 CLSD
Fuel SYS 2 CLSD
REL TPS 4.7%
THROT CMD 24.3%
ABS TPS B 33.3%
ACC POS D 18.0%
ACC POS E 18.0%
EVAP PURGE 0.0%
CMD EQ RAT 0.994
VPWR 14.668
 

PaulLR3

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I know you are looking for a technical answer but I'm thinking bad gas or failing fuel pump. A dealer may be able to solve this mystery much faster than our guesses.
 

VinnyAllenMX

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Thanks Paul, but the gas tank has been run out and refueled and the pressure reading on the rail is what it should be. So I've eliminated those two potential problems I believe.
 

BrandonM7

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The sensor probably presents either varying voltage or varying resistance to represent a value, both of which could be wrong if the connections are corroded or loose, or the wiring is maybe chafed somewhere along the run. You could jumper the plug at the sensor end and then measure the impedance across the loop at the ECU end, but since you don't know what it's supposed to be the answer may not be obvious. It would be a PITA, but visually inspecting the wiring and cleaning out any connectors and making sure there aren't loose wires in the plugs is what I would do next.
 

dwizum

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Digging up an old thread, did this problem ever get solved? Anyone else have input?

My truck is doing the same thing, threw P0087 and went into restricted performance on a trip this weekend. It had actually thrown this code one or two other times late last winter but it went away on it's own in a few minutes and didn't go into restricted performance. This time, over the weekend, it went into restricted performance three times and the light has stayed on. I cleared it with a code reader but I'm worried the problem will persist.

I've only had it for about 8 or 9 months, it was being driven by a relative of the dealer's owner for the last several years. Dealer had replaced much of the fuel system over the year prior to me buying it (pump, filter, all 8 injectors, several sensors). I'm wondering if he was chasing the same issue.
 

Nathan Ramsey

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Hi guys,

I’m likewise curious if this problem has been solved. I previously owned a 2001 Disco 2 about 10 years ago and am mad at myself for ever getting rid of it. Being that I miss it so much, I’m looking at a 2012 LR4 with 100k miles on it for $13,900. The seller says it’s throwing the P0087 and P0086 (haven’t found anything on P0086 anywhere) and probably needs a new fuel pump. If I end up going to look at it, I definitely plan on having a LR dealer give it a look over before I would consider purchasing it. I’ve been looking all over to see if anyone has found a solution to this somewhat common P0087 code problem and it seems a good amount of people are suggesting it’s the high pressure pump. Any advice/solutions on this situation? Also, does anyone know rough costs for the dealer to replace the high/low pressure fuel pumps?
 

ryanjl

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In my experience, Land Rover dealers are more than happy to tell you how much something will cost if you call them up. They've become deft at bringing bad news.
 

cperez

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In my experience, Land Rover dealers are more than happy to tell you how much something will cost if you call them up. They've become deft at bringing bad news.

You have to wonder if this explosive upcharging we're hearing about at the dealers is related to the massive belt-tightening going on right now across J/LR.
 

stl8grey

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What was the final remedy? I am trying to fix a P0087 stalling issue as well.
 

BeemerNut

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From what i've been told the LR4's have three fuel pumps, one the low pressure in the tank plus two high pressure pumps which are connected to a common "Y" with HP fuel to one location.
Fine and dandy should one high pressure pump fail your still driving on the other high pressure pump without any fueling problems or symptoms. Once the second HP pumps begins to fail you'll have problems and before that you never knew the first HP pump had already failed.
On the HP side it's something like 2-3,000 psi considered low pressure not even close to HP in my aviation hydraulics. b
Those HP pumps are inside the engine, also if they skipped a tooth the timing as well fuel pressures will be off involving timing chain issues the "high tech" 5.0 engines are having.
Reading on another LR site someone mentioned retiming the pumps after they skipped a tooth a practice used before trading in a LR vehicle so it will run normally again. Dirty practices dumping expensive repair problems onto another future LR owner. Same site read of a LR4 owner spending $2,500 and now up to $4,000 with the problem still not solved by throwing parts at it. Was told there should be a pressure port on them LR3's and 4's allowing for fuel pressure readings besides the $170 to $199 HP fuel regulator replacement costs. No clue HP pump $$$$ costs.


In the past somewhere reading fuel rail as well regulator for D1 and D2 series LR, forget abut them they only run at 2.5 BAR fuel rail pressures with an in tank LP fuel pump also dirt cheap replacement cross reference to GM part numbers.
Also a D1 or D2 will read at and below to minimum spec fuel rail pressures even with a brand new LR (rubbish) regulator. A D1 (not D2's) a direct install a 3.0 BAR regulator as used on BMW's to get the rail pressure into the normal spec range, (app 1.5 psi above shop manual's max pressure). Way better injector spray pattern vs the low dribble.
 

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