Discovery II v8 fuel delivery problem

[jiri_j]

Hello guys,

yesterday I had a problem with fuel delivery on my Disco II v8 2001 when driving on reserve. The fuel gauge was showing there is still some petrol left in the tank (after refilling the tank I calculated there was still 5 litres of petrol left in the fuel tank; also I drove only 30km after the fuel indicator showed I was driving on reserve - normally I can drive around 65km on reserve). In the middle of intersection the truck stopped - it was obvious there is something wrong with fuel delivery. This was surprise for me as I expected to drive another 30km before refilling (I was actually driving to the service station https://www.aulro.com/afvb/images/imported/2009/11/452.jpg).

I went to get some petrol and filled the tank with 4 litres just to get to the service station which was 1km away. I started the truck (after turning on and off the key several times into position I to pump some petrol) but the engine was idling poorly and after one minute stopped. I filled the tank with another 4 litres of petrol and started the truck again, now with success. The car is driving perfectly since then.

Any suggestion what was wrong with fuel delivery? I am pretty sure there was at least 5 litres left in the tank when this happened. Do you think it is just water in the fuel, or dirty fuel filter? Is there any way to depressurise the fuel delivery system without testbook so I can check the filters? Not sure if this helps: we had a very warm day yesterday with temperatures around 38'C.

Thank you for any advice or suggestion!
Cheers
Jiri

[Pedro_The_Swift]

hmm We have only run it out once,,
put a 5 litre can in and it started as normal.

I reckon about 30 kays from the light.


and there is NO filter,,
just a strainer at the bottom of the tank/pump.


maybe one injector didnt bleed properly,,

[justinc]

hmm We have only run it out once,,
put a 5 litre can in and it started as normal.

I reckon about 30 kays from the light.


and there is NO filter,,
just a strainer at the bottom of the tank/pump.


maybe one injector didnt bleed properly,,

There is a filter, it is part of the pump assembly, non serviceable:mad:

JC

[Blknight.aus]

the pump may be on the way out and over heating.

[PhilipA]

Remember that a Thor has a one way injection system. There is no return to the tank.

So It is theoretically possible that the engine kept running until the pressure dropped so low that it stopped, and almost the entire fuel line and rail were empty. Then when you put new fuel in the pump pumped fuel up against a big bubble of air with nowhere to go except a bit through the injectors.. This does not apply to a 14CUX as the air would be pushed out the regulator and back to the tank via the return line.


Mt guess is that if you would have kept cranking it would have eventually started with the first four litres, after it got rid of the air in the system.

Regard sPhilip A

[Pedro_The_Swift]

just to add to Phillips,,
when mine stopped, NO attempt was made to restart untill the refuel.

[jiri_j]

Hello guys,
I thank all of you for your comments. Greatly appreciated!

I do not drive with near-to-empty tank normally. I also use quality fuel - mostly Shell. However it might be true that I could pick some piece of garbage somewhere.

The most reasonable explanation could be, however, that it was caused by overheating pump as you guys suggested here. It was really warm that day. I will make sure that the tank won't drop below 1/8 in the future so the pump is cooled properly by fuel.

Is there any simple test to check if the fuel pump works correctly after this happened? Do you think I could nearly kill it if this happened to me just once only?

And also (sorry for these stupid questions, I am still learning) questions regarding injectors: is there any way to clean them? Do fuel additives work? How to find if they work properly? Or if e.g. one of them is blocked? Engine power test?

Thank you again!
Regards
Jiri

[Discobaker]

I've used the Wynns brand of injector cleaner before but only in fords, I just used the whole bottle even though it says it will take care of 4 tanks and that's has always seemed to do the trick. Dirty fuel is a problem no matter where and what you use, I always try and avoid anything under 1/4 of a tank to be as safe as possible.

[Pedro_The_Swift]

I'm not sure what running around with half full tank will accomplish,,

[Pedro_The_Swift]

There is a filter, it is part of the pump assembly, non serviceable:mad:

JC
Justin,, do mean a fibre strainer like at the bottom of the D1?

[buzz66]

the pump may be on the way out and over heating.

This sounds right to me too.
The Knight didn't spell it out but the pump likes to have fuel around it to keep it cool, so running low levels a lot is not good.
The normal fuel pump strainer is very large. No way you can block it up and cause issues.
If the pump has done 200,000 KM' s then it's time to change it.

[jiri_j]

Hello guys,

some time ago I had a problem with fuel delivery of D2 V8 2001 130.000km. In summary: when driving on reserve with 5 litres of fuel left in the tank, the truck stoped ( "ran out of fuel" ) when waiting on lights. It was pretty warm that day - around 39'C. Some of you suggested that the fuel pump probably overheated or could be at the end of its life.

Since this happened, I drove of around 1000km. I have a felling that the truck is a bit lazy like never before and I noticed an increased fuel consumption - 19 l/100km versus 16.5 l/100km before. Do you think that the increased fuel consumption might have a connection with the fuel pump?

I visited my LR mechanic and told him about the problem. He thinks that if the pump would't work properly, there wouldn't be enough pressure in the tank and the truck wouldn't even start if the fuel pump is the issue. A full testbook diagnosis was done and this didn't show there is anything wrong at all. I changed MAF couple of weeks ago (genuine part) so I don't think the MAF is the problem. Any suggestions?

Thank you!
Cheers
Jiri