Thanks for the additional information. I've replaced the fuel pressure sensor twice now, as I was hoping the first one was bad. I've checked the wiring by the pump and it seems okay. I've actually only seen the fuel level drop to zero once, despite it hitting limp mode multiple times. The wife still loves the car, but wanted one that was more reliable, so I bought her a 2014... So now the '08 has become my project to try and fix up without the stress!

I installed a new crankshaft position sensor and did the hill climb route again today. It's about 3km long with a 8% grade. After the fourth attempt I noticed the chugging again. I captured some logs this time. Maybe they can shed some light as to what is going on. I don't know if this is normal, but it looks like the fuel pump is unable to keep up with the pressure over time. (I'm only showing the first 30 seconds or so, as I should have gotten up to cruising speed by then)


First climb up the hill. (0-100km and then sustained 90-100km/h) The fuel pump duty % and pressures look normal. The workshop manual says the car will try and keep the fuel pressure at 55 psi.


2nd run.


3rd run. Duty is now pinned at 80%. (Not sure why it doesn't try and go to 100%?)


5th and final run i did for the day. pressures are way down.


I captured some idling (with taps of the throttle). I don't think the duty % should be maxed out when idling. Pressures are also well below 55.

 

I looked but haven't seen the answer... did you hook up the car to a reader that can give you the LR2 specific versions of the codes the system is reporting, as I suggested?

 

I haven't had a new engine code pop up for a couple months now. I must have reset the codes with my bad reader before hand and nothing has triggered it since.

 

Some codes won't "pop up". Take it to an auto parts store or a mechanic who has a reader that understands all the LR2 modules. You're trying to troubleshoot this somewhat in the blind without having that additional, more detailed info.

 

I have the GAP Diagnostics IIDTool. I'm fairly confident it can detect and read all the land rover codes.

 

the GAP IIDTool cannot do everything that the JLR SDD software can do, and many of the module updates are separate purchases. You can see the functionality gaps here:

https://www.gap-diagnostic.com/products/iidtool/

Enter your model and year. All I can do is suggest. Up to you if you want the additional info that may be there.

 

You need to read the Technical Bulletin more carefully

1. The bulletin identifies a P0628 this is a generic code and any code reader will detect this code and it states if you have this code then the software needs to be updated and not to replace any fuel system related parts.

2. No where in the bulletin does it reference any LAND ROVER specific codes. Therefore expecting a Dealership Level Diagnostic tool to give a code that a simpler tool won't is an unreasonable assumption.

3. The Bulletin discusses two anomalous condition that will be caused by the wiring harness - Erratic Fuel Gauge and/or Loss of Fuel Pressure

4. Focusing on the Loss of Fuel Pressure the Bulletin indicated that any of these could be true
- Connector wiring may be strained (and causing the --> Erratic Fuel Gauge and/or Loss of Fuel Pressure)
- The connector pins may be displaced (and causing the --> Erratic Fuel Gauge and/or Loss of Fuel Pressure)

5. The Bulletin instructs to remove the connector and inspect the contacts to ensure that the contact is seated correctly in the housing

Based on this I don't see any value to getting a more sophisticated tool to talk to your LR2.

If you want to make an independent measurement of the current going to the fuel pump then you can use a meter that will measure the current for the the fuse to the Fuel Pump control module. I've made this measurement in the past when I was looking at a different problem. The important consideration is that the current going to the module should increase with the duty cycle and if that is not the case then something is preventing the current from getting to the fuel pump. A high resistance contact will have this type of effect.

Conversely if the current does go up significantly but the fuel pressure doesn't then the fuel pump is likely past its best by date.

Here is what I bought to measure the current.




Remove the connector and inspect the pins and adjust the position of the wires and let us know if you still have the problem. If you do then its time to measure the current.

Good luck

Paul


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> Based on this I don't see any value to getting a more sophisticated tool to talk to your LR2.

Only if that is indeed the problem... from my experience, the graphs he posted don't point to a connector or wiring problem, based on the granularity of the fuel rail pressure, but we could all be wrong.

When the problem is a loose connection or stressed wiring, in virtually 100% of the cases you can make it happen by moving the wire bundle or jogging the connector.

 

RK21,

You may also want to consider logging the behavior of the fuel pump on a cold start.

I wrote this on the other board

"I did a cold start today.

0 PSI before I engaged the starter motor


On initial startup the fuel pressure spiked to 69 PSI

Then it dropped almost instantly 61 PSI


The interesting thing to note is that the RPM dropped to ~800 RPM before the fuel pressure dropped.

It took a few seconds for the pressure to drop to 55 PSI


The RPM drop seems to be attributed to the Throttle position

14.1% --> high idle

3.5% --> low idle"


The spike in pressure is intentional, the ECU is doing it to make the fuel a finer mist that is easier to ignite.

Check to see if your LR2 is doing this.

Log it if possible so that we can see the data.

Here is the link that I am quoting https://www.freel2.com/forum/topic37689-15.html


Note: if your fuel pump can't get to a higher pressure on a cold start then it is probably time to start talking about it in the past tense. Check it more than once because you have an intermittent problem.

Good luck


Paul

 

Thanks again for the continued help.

I followed the bulletins instructions, removed inspected and cleaned the contacts. The wiring was in the correct position. I also pulled up and yanked in different directions on the wires while watching the fuel gauge and didn't see any anomalies.

The "fuse buddy tester" is on order from amazon. I'll let you know the results once I get it in and retest on the hill climbs.

I logged the behaviour of a cold start this morning, and it pretty much follows exactly how you described. Is it possible for fuel pumps to 'fatigue' over time while running?