Thread: Rhythmic loss of power under load - new common rail Defender

Bit of an odd one Bill. Certainly sounds like a fuel problem, like air is being introduced into the system. Has the MIL (engine warning) light come on?

Cheers,

Thanks for reply Tim. No the MIL light does not come on when I have this problem.
Bill

Another thing Tim. I agree that it is likely to do with air getting into the fuel system. There is a green plastic screw top on a brass thread at the very top of the fuel delivery line - before it goes down to the injector pump. Do you know whether this is also an air bleed valve and should it it let out air before the fuel goes down to the pump? The mechanic from Alice Springs LR who helped me when I had broken down on the Great Central Road said the problem sounded like air going into the injector pump which makes it shut off allowing the air to go back up the line, then when the injector pump comes in again it drags the air back in - and so on. It sounds logical.
Bill

You may well need to drain your tank, pull the pump and clear the filter in the bottom...

Sounds like the corrugations are stirring the bottom of the tank up and blocking the pump.

Thanks Thombie. I removed the tank beside the road when we broke down thinking the same thing. But there is no pump in the tank in the common rail models. Just a pick-up and guage. And it was pretty clean. The fuel delivery is via a lift pump in the motor compartment. I suspect air in the system.
Bill

Sorry. Tombie.
Bill

Originally Posted by Billj18

Another thing Tim. I agree that it is likely to do with air getting into the fuel system. There is a green plastic screw top on a brass thread at the very top of the fuel delivery line - before it goes down to the injector pump. Do you know whether this is also an air bleed valve and should it it let out air before the fuel goes down to the pump? The mechanic from Alice Springs LR who helped me when I had broken down on the Great Central Road said the problem sounded like air going into the injector pump which makes it shut off allowing the air to go back up the line, then when the injector pump comes in again it drags the air back in - and so on. It sounds logical.
Bill

Pretty strange that you have no warning light, however I can not see a fault for low fuel rail pressure in the manual. Sounds like the vibration from the corroguations is causing one of the quick connect fittings to move and let air in, (I'm not to sure what the green plastic cover is for, possibly a fitting for attaching a vac gauge??). Sounds like a vacuum leak down test on the fuel supply system needs to be done to try and find the leak. Of course it could be something obscure like the throttle pedal sensor.....

If the vehicle is still under warranty I'd suggest getting LR to sort it out, you don't want to be in a position where LR can say "you've been fooling around with it, it's your fault". They also have the test gear to see if there are any faults logged in the ECU which can point them in the right direction.

Best of luck!

Tim

Edit: The fitting is a bleed valve, from the manual:

BLEED VALVE
The bleed valve is located in the fuel feed line near to the injector pump. It facilitates the use of a vacuum connection
to prime the fuel system and remove air during initial and service primes. This protects the injector pump from air
locking.

Thanks again Tim.
It is under warranty. I have it booked in with LR at Barbagallos next Monday and will leave it with them for as long as it takes.
I will let you know how I go.
Regards,
Bill