Hi..

Hopefully i can help.

I do know on these the 2 electric lift pumps are very common for failing on those cars aswell as the MG ZT as i have replaced quite a few - The usual sign in some cases is the the under bonnet pump becomes alot louder than usual or beings to stop completely -sometimes a tap with the end of screwdriver can knock it back into life.- but usually any problems with that is a sure sign that the "in tank" pump is failing or has stopped completely putting extra strain on the one pump to drag the fuel through upto the engine/filter..so if the in tank one hasn't been checked then i would certainly start there - you can locate it by lifting the back seat and remove the black cover 4 x 10mm bolts on the drivers side in the back and see if you listen for the pump working when the ignition is turned - If not..then check to make sure its actually getting a feed from via the multiplug thats connected there using a test light or multimeter - If it has when the ignition is turned then the pump is most likly the issue if not then you'll need to trace back the wiring and also check fuel lift pump relay on the fuse relay panel fasia at the passenger side ,so seeing as you haven't mentioned that upto now then i would double check on that - Also replacing the under bonnet fuel filter maybe one option to try too which has already been done - Also check the glowplugs are actually working all 4 - check The cam & crank sensors sometimes these can cause issues more the cam sensor - as to can the fuel pressure sensor at the under bonnet filter / rail pressure sensor - The High pressure pump which is run via the timing chain very rarely fails on these so can't really see that being at fault - I would also double check anyway inside main plenum on the passenger side below the bottom of the windscreen you'll need to remove the plastic mesh lid and then a black plastic cover which you slide out - may need to remove that rubber seal along the back of the engine bay.and inside you should see a black box that houses the main ECU and pollen filter..just double check to be sure everything is dry and the ecu mounted on its holder and there is no signs of rain water building up in there - quite often is the ecu is getting wet etc than can cause a whole load of problems and in some cases lead to the ecu needing replaced..however as you haven't stated the in tank pump being checked than i would maybe start there first..unless there are any EML lights up on the dash too since this fualt has occured then it may require a diagnostic machine if thats the case to retrive any fualt codes..