My L405 SDV8 low mileage (18.600 miles / 30.000 km) had a B service (oil + fuel filter change) done a month ago. Service history is as per recommendation although with the low mileage not done every year. Last time for fuel filter change was 2018.

After the service, I have an intermittent starting problem where the car cranks but won't start. Error code Low Fuel Pressure (P0087). Initial idea was that the in-tank fuel pump was dead and it was replaced after the car did not start any longer (apparently a not uncommon issue). Power supply was checked and pressure measured at the fuel filter seemed low.

The problem, however, persists. It is regardless if the engine is hot or cold. Every 20 start is a crank but no start. Oftentimes when driven and then left for 10 minutes. It simply won't start. If it starts, the engine does not idle well and then stops after 5 seconds with error code Low Fuel Pressure. Engine light is then turned on but disappears after 2 days.

The idea now is that it might be the fuel pressure regulator on the manifold. The latter is apparently also a not uncommon issue. We've ordered a new one in combination with secondary fuel pump and pressure sensor on the manifold.

I hear a humming sound from the secondary fuel pump and I guess it might be blown as well from the fuel pressure regulator not being able to close 100% or at least from time to time doesn't. The noise started when (I think) the in-tank fuel pump collapsed.

My guess is that the fuel filter was blocked after 6 years of no change, and potentially in combination with the regulator not closing 100%, destroyed both fuel pumps. Potentially, only the regulator was the issue. It probably happened before me and the seller never informed me. When I needed to engage N for towing to the workshop I saw the lever wasn't fastened down and hence I guess it had happened intermittent before.

Any other idea is most welcome!

Last edited by niklasel on 5th Dec 2024 10:53am. Edited 4 times in total

Is there a way of checking the actual fuel pressure with a gauge? I don't know if there is but that's where I'd be headed in an effort to avoid throwing parts at it!

I do like Stockholm!

Chris

Yes there is a fuel gauge where the filter is situated. But then I need to drive around with it attached along with decoding equipment etc. I was hoping to avoid buying equipment and tools but maybe that’s what Land Rovers are all about (trouble shooting)

I was envisaging a simple, capillary type gauge, or a vac /pressure gauge, which is a very useful, cheap diagnostic tool, nothing special!

Chris

So now the secondary auxiliary fuel pump died as I expected. The humming sound was gone one morning and the car started but gets no fuel and eventually dies. Workshop ordered a pump in Oct but it never came so I ordered one myself now. Due to arrive shortly. Will try to replace it myself although it looks pretty tight down there under the ECM. Any tips here?

It's more than 2 months without a proper functioning car now. So miserable.

I think the in-tank pump died which killed the secondary pump which ran dry / overheated.

Workshop still claims it could be the fuel pressure regulator. Will probably replace that one too.

Hate this car.

The auxiliary secondary fuel pump OEM (from Hella) arrived on Fri 6.12 and today I installed it myself. Original part was a polish brand.

Quite tight down there but no need to remove the panel (secondary bulkhead left panel) as the workshop manual suggests. Clamp size is 12-14mm. Most clamps are quick release. Also, do not remove the auxiliary fuel pump nuts (2 of them) but rather remove the entire panel (3 nuts) as they are fix welded. The 2 pump nuts are not and starts to spin and you need to hold the screw on the backside of the panel (not possible). Rubber protection came off easily with silicon lubricant.

It starts and runs smoothly. Much better response from the throttle. So happy that I fixed it myself.

Let's see if the intermittent starting problem persists. Will replace the fuel pressure regulator then.

Well done, a satisfying outcome, are you loving it a bit more now..? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

As long as it runs I love this car. I guess a low mileage car would suffer from the nowadays “healthy” diesel provided. Not sure the additional work creates less CO2 emissions eventually.

So I ran the car for an hour now and noticed that the secondary pump became louder and louder. I opened the fuel cap and there was a substantial vacuum.

2 new pumps but something is still wrong. Is there something wrong with the return line? Can this be the fuel pressure regulator? If it's leaking, the HPFP might have to run really fast and thus put pressure on the auxiliary LPFP.

Really would appreciate someone who really knows the system here.

Last edited by niklasel on 9th Dec 2024 6:27am. Edited 1 time in total

Have you checked the vent in the filler cap?

I ran the car without the filler cap and the noise is still there... this issue came just some weeks ago. Can't imagine the cap is the issue all of a sudden. This car is almost brand new. Zero dirt anywhere.

I think the new pump is already blown...

I drove the car to the most renowned LR dealer in greater area Stockholm and they said the car is fine. No issues. Loud buzzing sound from auxiliary fuel pump is due to pump being OEM and not LR original they claim. OEM pump from Hella. Absolutely not sure here but who knows.

I now ordered a new original pump and let's see if the humming stops. LR offered the change at 1.2kEUR incl. part but I ordered the genuine pump for 0.2kEUR. Need to buy Christmas presents.

Since no one answers these posts with some insights I conclude that people either don't fiddle around with the L405's much or this is a very unique problem.

At least, since I replaced the pumps the car always starts.