LR2 friends,

I need you to include more information when you post

For example do you have

1) a 6 cylinder naturally asperated 3.2 Liter Gasoline powered engine

or

2) a 4 cylinder turbocharged 2.0 Liter Gasoline powered engine


This thread is for option 1

If you are discussing your experience with option 2 then please disclose that in your reply or start a new thread.

I am not familiar with the 2.0T that Land Rover used in later LR2's. However my Audi 2.0T is direct injected and it does have a mechanical fuel pump on the engine and I suspect that the 2.0T LR2 has the same.

Some things to think about

A) If the ECU and Mechanical gauge differ by 14.7 PSI then it is likely that one of these is an absolute measurement and the other is a relative measurement. (For example I inflate my Tyres to 35 PSI @ seal level as measured on a gauge if the Atmosphere were removed (i.e. Put the Tyres in a Vacuum) then the pressure would be 49.7 PSI.

B) The fuel pump is controlled by the ECU to generate the pressure needed by the engine. The Fuel pressure sending unit (on the 3.2) is a know failure point and it will cause drivability issues and set the MIL.

C) The fuel pump needs a good power and ground connection to run correctly. If either is poor then the ECU will increase the PWM (duty cycle if you will) of the pump to compensate. A S80 3.2 owner (LR2 first cousin once removed) had problems with his fuel pressure that were traced to a bad ground connection.

D) The fuel trims are important to check. If you see a high number, something above 10% then you need to figure out why the ENGINE needs a lot more fuel than the baseline setting.

E) For the 3.2 a bad Purge Valve (fuel vapor recovery) can cause problems. I have a new valve and plan to replace it soon. I did get insanely rough running and a MIL once about 2 months ago.

Some of this information is applicable to the 2.0T but most is only for the 3.2.

Hopefully this helps

​​​​​​​Paul

 

Hi Paul,

Thank you for the immense wealth of information you've provided. I've lurked many other forum posts and it's helped me diagnose other issues as well!

My vehicle is an '08 lr2 3.2L gas with 400,000 kms on it.

A) I haven't compared fuel rail psi numbers.

B) I've replaced that component twice to no avail. Although the rubber grommet on the electrical plug has deteriorated and wouldn't plug in completely with it (it seemed to have expanded or something?), so I took it out and smothered the connection point with dielectric grease. Is it worth sourcing an intact plug with the grommet to replace it?

C) Where is a good place to look for a bad ground for this? Do I have to drop the tank to gain access to the fuel pump plug?

D) Haven't checked.

E) I replaced the Purge Valve last summer.

Thanks, Riley

 

A) No worries..............work on the other items first

B) Yes get a new receptacle and the tools to extract the terminals and switch things over (I don't know the part number for this, but Volvo likely sells it)

C) Two things to check
1) The ground of the control module (see map below, I don't know which point is correct)
2) The wiring harness read these
https://www.freel2.com/forum/topic36980.html
https://www.freel2.com/forum/topic29...el+pump+ground

D) Fix the other thing first, but the Fuel Trims will tell you if you are successful (if the LTFT is -10 and you replace the receptacle and it goes to 1.0......success!!!!!)

E) We are going to need a lot more details about what you have replaced.........enquiring minds want to know.....not just this a long list would be helpful



Fuel pump module ground is one of these



My recommendation is to fix the connector for the (Volvo calls it a receptacle) for the fuel pressure sending unit first. And don't add any dielectric grease, you only need a very small amount and you likely already have that. Note: I would replace the plastic connector instead of soldering in new wires.

After that I would search for the ground and replace the fuses and relays for the power for the fuel pump module.

Post you results here and we can discuss more

Take care

Paul

 

I am 99% certain that the fuel pump module is this part



Its mounted below the Sirius satellite radio

You will find it here

https://www.freel2.com/forum/topic36819.html

Take care

Paul

 

The problem with diagnosing P0087/88 codes is that there are four subvariants of 87 and five of 88, and you won't know which one it is unless you read the codes with a box that can talk to the modules.

The good news is that all the 87 codes have similar possible causes:

• Fuel rail pressure sensor circuit short circuit to ground, short circuit to power, open circuit, high resistance
• Fuel starvation
• Fuel lines leaking
• Fuel lines restricted
• Blocked air filter

One of the 88 codes has the same possible causes, but one says this:

• Fuel lines restricted
• Pressure control valve circuit short circuit to power
• Pressure control valve

...another says this:

• Leaking fuel system
• Volume control valve circuit short circuit to ground, open circuit
• Volume control valve stuck open

...another says this:

• Leaking fuel system
• Pressure control valve stuck
• Pressure control valve circuit short circuit to ground, short circuit to power, open circuit

...and the last one says this:

• Leak in high pressure section
• Injector nozzle stuck open/worn
• Worn high pressure pump, filter blocked
• Leaking pressure control valve
• Low pressure section pressure low (leak in system, pump output low)

To get the full picture you need to read the full codes. Don't have a reader that can do that? Most auto parts stores will do that for you, for free.

Once you know which specific code you have, the service manual guides you as to what to do, but it isn't always accurate. That's where calibrated eyeballs like Paul's come in.

 

If you can get the complete code you should..........that would help.

The one thing to be careful about is your LR2 is old enough and with enough miles that it may have failure modes that the Land Rover team didn't anticipate.

I looked up the grounding point for the fuel pump module and its G4D149B-1 that is the drivers side rear close to the module (under the Sirius Satellite radio module)

If you measure the voltage drop from Black wire with the Gray stripe to Battery (-) with the engine running you should get something like 0.050V if you get 0.200 Volts or higher then you have a grounding problem. (you can back probe it at the module if you like instead of searching for the grounding point.)

You can also check the Voltage drop on the + side the Brown wire with the Yellow stripe to Battery (+) with the engine running should also be 50 miliVolts or less.
The lower the better for these measurements.

The other wires are
Yellow with a Grey stripe Motor +
White with a Brown stripe Motor -
Yellow with an Orange stripe (this is the control line where the ECU tells the controller how much to run to get the desired pressure)

I did this for my ignition coils on the cylinder head and it was about 0.050V if you prefer 50 miliVolts......same thing
(0.050V = 50 miliVolts)

The ignition coil measurement is easy to do. Try measuring that first and see what you get.
Red lead on the crimped copper and black lead on battery (-)
This is for my Volvo 3.2 which is identical to my Land Rover 3.2
https://www.matthewsvolvosite.com/fo...ic.php?t=98362




Having said all of that you should replace the receptacle first. Everything depends on the ECU getting an accurate measurement of the fuel pressure.

 

He's only got 100k km more than I do.

 

Thank you all for the information! I will investigate and let you know the results.

 

Quick update:

Sorry for the delayed reply. It drives fine around town so I had to wait until I was going to take it on an extended drive with the 'fixes' in place before I could report back. Unfortunately the problem still persists.

I replaced the receptacle, replaced the fuel pump control module, replaced the fuse F22. (F17 in the engine fuse box is a 60amp and I didn't have a replacement for it/looks fine). The relay above F22 looks like it's soldered onto the board so I didn't figure out how to easily test/replace that one.
Tested the ground for the fuel pump control module and it was at 0.050V so that seems fine. Any other grounds I should test?

I guess next step is getting a fuel rail pressure tester as well as access to a better obd2 reader. Any recommendations for that?

Two things to note that I didn't note previously is that:

• One time when the car 'died', the fuel gauge read empty. When it finally started up again, the gauge slowly went back up to the accurate fuel level. (it only did that once)
• It seems to 'die' more when the weather is very hot outside. (+25 degrees C). My wife took it for a drive yesterday in +35 and it died within 45min on a slight incline, as opposed to usually taking a few hours to 'die' when the weather is warm and only on large hills.

I know this is for a Discovery II, but could my problem be something similar? https://landroverforums.com/forum/di...804/#post75939

My uncle tells me it's the fuel pump. I don't notice any excess noise coming from the fuel pump location indicating it's failing, but I'll try driving around with the seat folded down and the flap exposed to see if anything becomes more obvious.

Thanks again for your help.

 

So, I'm not an expert in diagnosing the actual issue BUT, if it's the fuel pump, keep the tank close to full and that should avoid the pump issue for the time being?