2005 Forester cuts out when warm!

[BushBart]

Hi,

Desperate to save my XT turbo.  Variant SG9 version 560.  Reg'd December 2005.  Done about 102,000 miles.

About seven months ago I noticed a low level thumping/knocking noise.  You could hear it at idle inside the car but not outside.  My mechanic and I could not find the source.  The car ran fine so I carried on using it and just accepted the noise, which wasn't audible when driving.  Then a month ago one morning it would crank but won't fire up!  I could hear the fuel pump priming but it just would not fire up.  Called recovery who thought because parked on a slope and only had 1/4 of tank of fuel it might not be getting enough fuel. Got car level and cranked again whilst the recovery guy sprayed starter fluid in through the air box.  It almost started but wouldn't fire up.  We put some fuel in but again it would crank but wouldn't start so it was dropped off with my mechanic.  He replaced the fuel pump and it started, however, it was very lumpy.  When he took the old fuel pump apart he noticed bits inside had deteriorated and most were missing.  Injectors were checked out.  Now we have the car starting from cold fine, running okay but as the car gets warmer the thumping/knocking noise gets louder and then the car cuts out, even when driving along.  It will crank but won't start until it is cold again.  Crank sensor has been changed but hasn't fixed problem.  Battery is fairly new and has plenty of power.  He's going to try replacing fuel temperature switch to see if that solves the problem whilst I do some more research and send out this SOS.

If anyone has any hints or tips on solving this puzzle I would really appreciated it.  

Are there any mobile specialists in the South East?

Thanks

[Mr B]

If fuel pump been going bad you had lot of potential running with fuel ratio lean.

I would be suspecting engine damage .
Your garage wants inspect cylinders with plugs removed and do a compression test .
They also want test the ease of turning engine cold to ease when warmed up and cuts out .
Piston and bottom engine damage fairly common when been running long durations with major faults  ...

[BushBart]

Thanks for the advice.  We checked cylinders and compression but all okay.

Anyhow, problem solved thanks to Dan at Surrey Subaru Specialists.  The fuel pressure regulator was replaced and she runs fine now, although I can still detect a faint thumping/knocking sound, at idle only, which we cannot pinpoint the location of at the moment - you cannot hear it outside!  Have read this could be fuel line damper so will investigate at some point.