Fuel Pressure drop overnight & Hig Emissions
 

Here's one for the more knowledgeable: - my old, otherwise very reliable D5 AWD XC90 had always run sweet but recently its become harder to start in mornings, only occurs when cold and left for more than 8 hours, usually overnight. Last week it went into limp mode and won't re-set. Messages say Engine service required and High Emissions service required. Its as if the fuel pressure drops to nothing overnight and although this required a bit of effort to start, the problem has obviously got worse in last week. There was a slight weep of diesel at injector connector but this has been repaird. All glow plugs replaced as well in last service. My (very reliable) garage is saying its throwing-up all kinds of fault codes. Anyone overcome similar problems with a D5.
Its a 2004, D5 AWD, XC90, 130k miles.

Rail pressure dropping would indicate a leaking injector.

Where abouts are you? Wondering if I can get it on the diagnostics but don't know if it's driveable?

I'm in Lancaster. Left it with my mechanic. He recons fuel feed problem, not filter or tank pump, beyond that. Suggested a visit to Merlin in Preston after his code reader kept getting multiple codes, load of them. Reckons he can't erase Engine Service and Engine Service - High Emissions Code, they come back on as soon as he tries re-start. Its running, but only to about 2,000 revs. Changed Fuel Rail Pressure Sensor, still lacking power. Had a similar problem to this years ago with the wife's Picasso; general lack of power, turned-out that was the MAF Sensor. Tempted to order another from ebay - sensor only £25. Problem I have is getting to Merlin means taking a day off work. Would prefer to meet someone with a bit of D5 knowledge though and if you have a code reader, wouldn't mind limping through to see whether yours can locate a more definitive code.