Water in my Diesel Tank ...

This may be of absolutely no use to you, but just in case it is, somebody on a Volvo forum in the US who had water in their fuel in their V70 (but cannot ascertain whether they are petrol or diesel) and subsequent problems after clearing out - the thread refers to a 'balancing sensor' in the right hand sender or the pump

water in D5 fuel tank 

I have similar problem with 2003 V70 D5 , car stops dead when tank gets to 70% showing on fuel gauge , this has been going on a long time and is one of a number of problems , a new fuel pump was fitted and I know this was necessary because I have the old one sitting in front of me and I know for sure its knackered but now I think that the cross feed pipe not being connected or blocked is whats causing the problem and this must have happened at around the same time as the electric fuel pump conked out but because we thought we had got one problem we couldnt possibly have two . We set off on holiday with the new pump installed and then car stopped dead middle of nowhere in France cost 160 Euros for a breakdown truck to deliver diesel and the experienced mechanic who attended and lucky for me spoke some english had never seen this happen , sure enough put in 25L of deisel to show competely full and the car starts up again . I will now follow what you have done and take the sender units out and check the pipework . Incidentally I am also in Ireland and now I know why diesel costs 20p a litre less than england !

water in tank 

I had this problem once using a petrol tank pump to replace a faulty D5 tank pump which looked right and pumped fuel but it never worked properly , Fitted a new volvo unit and all was ok . There are all sorts of pressures and flow rates for these in tank pumps for different cars ... maybe the flow rate is all wrong . Your symptoms suggest the main pump is being starved . Have you got plenty of volume of fuel coming out the main pump feed pipe at the front when ignition is turned on? and is it 2 bar up the front ?

Clan Is there a simple test routine I could step through to exercise the LHS pickup. There is not enough slack in the link pipe to have the LHS pickup in-situ, whilst observing the output in the swirl pot. Rgds

yes theres plenty of fuel coming out the pipe entering the low pressure mechanical pump , the pressure was measured by a mechanic who I have some trust in , he was recommended by the local main dealer when they couldnt look at the car . I am open minded to the possibility that the Denso pump just isnt right wrt flow rates or something similar but when we compared the Bosch and the Denso side by side you would think they were made in the same factory , they look identical , the Denso pump came out of a 3L diesel Toyota . The car runs great until you get near the critical fuel level , its been going on so long that I am now on a mission to understand the problem , its more driving me mad that I cant understand whats happening than the actual inconvenience . I am also assuming that the electric fuel pump just has 12V or zero applied and has no voltage control to regulate the output pressure as its controlled by an on/off type relay ? The other problem is the 360 Euros I was quoted for an original replacement complete with sender unit ( parts supply only ) , had it been about half that price would have had bitten the bullet by now .

water in tank