V70 Engine Cutting Out
 

Have a 2003 D5 V70 with 147k miles. A few months ago had a problem with the engine cutting out, first loss of power, then warning message 'ENGINE SYSTEM SERVICE URGENT', went into low power mode then cut out after a few 100 yards. Restarted OK but re-occurred, at increasing frequency ( i.e. shorter and shorter distance). Called out AA, diagnosed low fuel pressure. Couldn't drive to garage due to frequency of cutting out (had to be towed). New fuel filter fitted, ran fine ....... till a few days ago when the same problem re-appeared. This time managed to drive to garage, they had no idea but I got them to replace the filter again out of desperation. Runs OK again (well I got home without the problem re-appearing), previous filter looks OK with no obvious clogging. Any ideas ? fuel pump ? electrical fault somewhere? pressure sensor ? Started fine each time it cut out.

take it to a diesel specialist who can test injectors and fuel pump etc

Mine was doing this.

It was the Bosch fuel pressure regulator on the side of the high pressure fuel pump, it started playing up when the engine gets up to temperature. Engine would never cut out when cold, only once a bit of temperature got into the engine, then it would randomly stall during low speed gear changes, or on the initial rev of the engine when trying to pull away. Or if it didnt stall entirely, the engine would stumble and go into limp mode with ENGINE SYSTEM SERVICE URGENT displayed.

Replaced the regulator 7 months ago which fixed the issue. Not had any problems whatsoever since then.

Be very observant if you order a replacement via ebay, because Euro 3 and Euro 4 D5 engines have a slightly different design of Fuel Pressure Regulator.

The Euro 3 item has THREE screws, and a connector plug that that points sideways, towards the airbox.

The Euro 4 item has TWO screws and a connector plug that points down towards the gearbox.

If that part does not resolve the issue, then it would be wise to get a diesel specialist to take a look and do some proper diagnosis to avoid wasting any further money.