Id be tempted to do away with the fuel filter housing and pipe the flow direct to the pump and see how it runs.

It may be leaking air in to the filter & check all rubber fuel hoses for splits.

Following on from the previous posts I too seem to have the same problem with my 2003/53 2.2Di Diesel X-Trail.

I replaced the fuel filter the other month and since then I have not been able to obtain the consistent performance I had previously. Genuine Nissan filter was used.

Whilst the engine always starts first time and idles smoothly, intermittently and when under load, i.e. accelerating up hill or towing, it will loose power in 3rd or 4th gear requiring a premature change down to 2nd in order to maintain progress. If I leave it in 3rd or 4th the power will intermittently surge. (You could call it spluttering!)

The problem I’m sure is down to fuel starvation caused by air in the fuel system that wasn't there before the filter change.

I have primed the system by removing the fuel filter outlet pipe ensuring no bubbles remain and then reconnect the pipe continuing to prime until the priming pump goes ‘hard’. However if left for 5 seconds it will go soft again and will take a few more pushes. I then start the engine and continue to prime for a few minutes in case any air is stuck beyond the filter.

This process fully restores the performance for a few weeks only for it to slowly revert to its previous state.

I have checked the filter housing/priming pump by installing a clear fuel pipe to the outlet, that loops higher than the filter, and there are no bubbles whilst engine is running.

What I do notice is when the engine is switched off a large bubble appears from the direction of the fuel pump and sits at the top of this loop. It clears when the engine is started but returns when stopped. I’m not sure if this is normal behaviour or whether it has anything to do with my intermittent issue? On disconnecting the clear filter outlet pipe the fuel immediately drains away, I assume back to the tank via the return pipes, again I assume this is normal too? - but the filter remains full as expected so the non-return valve is working ok.

So to diagnose this further my questions are :-

1/ Should the priming pump stay hard until the engine is started?
2/ Does it make any difference if the ignition (engine not started) is on when priming?
3/ Is it normal to have to continue to prime once the engine has started?
4/ Should an air bubble rise from the direction of the fuel pump to the fuel filter outlet when the engine is stopped? Or do I still have an air lock/leak maybe in the fuel pump area?
5/ Should the fuel drain away from beyond the fuel filter if I disconnect the filter outlet pipe or should it hold there waiting for the main fuel pump to suck it in and compress it?

All hose connections are tight and there are no obvious fuel or air leaks in the system that I can see.

I would welcome any comments, observations or advice so I can resolve this issue one and for all, and hopefully help others who are experiencing this frustrating problem.

Thanks in advance.

Without any warning my 2005 185k miles X Trail switches in to limp home mode, unable to accelerate. One click off and then back on the ignition reboots the car. It can go for months without doing it, or several times every 5 minutes. Seems to be a link with rural diesel from infrequently used garages. Nissan diagnostics many years ago said it was a faulty fuel pump, which was definitely wrong, as have driven another 100k miles on the same, original fuel pump. The most plausible explanation I have heard is that it is the potentiometer (which I understand is the accelerator by wire). It happens only at low acceleration, and never in cruise control. Now it is doing it several times a minute after filling with Waitrose petrol and the engine management warning light has come on. Am taking it to the garage and see if they can work out what the problem really is.