Thread: LR3 2006 4.4ltr, fuel issues which Land Rover cannot diagnose

Well, folks, I don't think you will have expected this response, but I think I have fixed it by replacing the fuel pump. More accurately, I think the replacing of the fuel pressure regulator has fixed the issue. I drove 160 miles at 40 degrees into strong wind, and she didn't miss a beat.

On the downside, I snagged a sensor float on something, as she reads 1/2 full or more all the time, and I have lost my front jet pump somehow (though I think that has happened because I pushed the free corrugated tube onto the blanked off fitting on the tank cover plate. I now think that hose must be the return from the front jet pump).

Tank is coming out Monday night to further rectify the issues I have engendered.

Well thats some good news. Very close now

About the gauge not reading right, I had the same problem when I changed the pumps in one of my Jags. When tightening the locking nut that holds it into the tank, the one of the pumps turned with the nut and the float arm was not in the right position & got caught up on something. Is there an arrow on the top of the pump that's meant to be pointing forwards?

Originally Posted by Cambo351

Is there an arrow on the top of the pump that's meant to be pointing forwards?

I'm not too sure. The pump does not seem to sit in its housing in any other way than it does as there is a flat on one side of the pump and a groove in which another location mark sits. I have a feeling that it is the front sender float which is caught on some of the framework within the tank. I'll have to have a feel as you can only get that sender out by shoving your hand into the tank to feel the part. It may not have been properly mounted. Either way, I think I am going to replace the two senders while I have the tank out. Both tank floats have fairly aggressive wear marks in them -- so it seems like they may catch on something when properly fitted!

Good to see persistance pays off.
Hopefully you have fixed it and helped others into the future by your work.
ENJOY
Andrew

Here we go folks:

The fuel pressure regulator was faulty permitting the pressure relief valve to drop to its proper (closed) position when the fuel pressure dropped as the pump was switched off with the key. The recent fuel issues were caused by not remembering how the tank parts were fitted due to the 3 months in-between fitting the removing the original tank and removing the replacement tank last week. The rear fuel sender had become faulty and was reading improperly. The stalling when low on fuel was due to accidentally blocking of the front jet pump return pipe instead of it mounting it in the clip on the top of the fuel pump.

All symptoms have now been eliminated.

Part of the difficulty in locating the fault was down to well respected mechanics and advisers being very sure that fuel pumps do not present as resetting and so ruling it out from our differential diagnosis when, it seems, that fuel pump regulators are able to reset if bypassing fuel at too lower pressure.

Thanks for all of your help, folks -- and I hope that this issue will be a much more easily solved issue if people ever come across it again! It has taken me 3 months and a week to resolve this issue and it has cost me $2200CAD in purchasing of unneeded parts and $600 for the correct part. I am fortunate to have a friend with patience and a shop who has helped me at night to go through all of these potential issues. I have racked up 57 hours of ramp time over three months -- charged at shop price here in Lethbridge, that would have been about $6500 on top of the parts cost.