2004 s8 d5 cutting out and engine system urgent service light on

[TERRYD]

Currently got a 2004 s80 d5 auto, which is being a pain n the neck,
after driving for various different miles the engine system service urgent light appears and sometimes the car dies, majority of the time it will fire back up others you need to give it a spray of easy start.
Replaced parts up to yet
in tank fuel pump genuine volvo
fuel filter housing genuine volvo not cheap
had injectors tested all ok
high pressure fuel pump
fuel rail sensor

i dont know what to do next keeps coming up with faults saying
fuel pressure too low
fuel pressure to high
can anyone help me with this matter its like im just throwing cash away
thanks

[Harvey]

sounds like you could have a air leak,or a sensor fault.
Just to ask what code reader are you useing to list the codes
Did this just start after any work was done on the car ?.
the code is saying the rail pressure is to high or low,what number code is being logged.

[TERRYD]

Using a snap on diag cant remember codes will get them off the diag 2moz.
Problem had started before changing any of these parts.
Its a pain iv had it at a local diesel specialist and they say all the pressures are right but thats normally the case you take it somewhere and it dunna play up

[LeeT5]

You need to get 'freeze frame' data from when the fault is logged, after you clear the DTC. That way, you'll see what state the engine was at when it logged the fault and what sensors were doing what.

Sounds to me like you've been (or your garage has been) jumping to the wrong conclusions, judging by the parts you've replaced and the money you've spent and yet, the fault still persists!!

Do yourself a favour, stop throwing money at it and drive it to a garage that actually knows what they are doing! No one here is going to diagnose your fault on the basis of what you have told us. Sorry to be blunt mate but it's a fact.
It could be many things, including (not mentioned so far) throttle body sticking and EGR valve sticking. If she cranks but does not fire up, yet live readings says you have the correct fuel rail pressure, then trust me when I say...It ain't a fuel problem so far as, everything is spot on up to the fuel rail! After that it only leaves injectors. Have you got an RPM signal on crank? If not, she won't fire up because the injectors will not be opening and closing.

If you need to use Easy start sometimes then I would start by looking at the EGR valve and or a possible leak in the fuel system and I don't mean a physical leak that you can see, I mean a leak back to tank.

Best of luck!

[jdavis]

Do the d5's have a fuel pressure regulator? Could be that.
Short of that take it to volvo, they will plug it in and diagnose the problem.

[LeeT5]

Do the d5's have a fuel pressure regulator? Could be that.
Short of that take it to volvo, they will plug it in and diagnose the problem.

All common rail diesels have a fuel rail pressure sensor AND a regulator.