Starting

[s40t4trowsdale]

Hi all,

I've had this problem since buying, but is getting worse as the time goes on, only in the last few months, before that odd times over a year period. My s40 1.8 auto, struggles to start, turning over a few times before starting, doesn't happen all the time, there is no structure to it like in the morning before work, can be any time after a drive to the shops, or anything, done a full service thinking it was that. the car has done 30k miles.

Thanks

Adam

[Laird Scooby]

When you say a full service, did that include the fuel filter? I'd also suggest something like Redex injection system cleaner as the first things to try, after that you'll be in to reading codes and trying to glean clues from that.

[gatos]

Originally Posted by s40t4trowsdale

Hi all,

I've had this problem since buying, but is getting worse as the time goes on, only in the last few months, before that odd times over a year period. My s40 1.8 auto, struggles to start, turning over a few times before starting, doesn't happen all the time, there is no structure to it like in the morning before work, can be any time after a drive to the shops, or anything, done a full service thinking it was that. the car has done 30k miles.

Thanks

Adam

Long cranking times and difficulty staring the car, are usually due to the FPR, fuel pressure regulator

[s40t4trowsdale]

Originally Posted by gatos

Long cranking times and difficulty staring the car, are usually due to the FPR, fuel pressure regulator

What does that do? Where is it on the car

[gatos]

Regulates the fuel pressure to 3 bar for a steady fuel supply. If you Google for, Volvo, long cranking, not starting etc, FPR seems to cause the issue quite a few times.

[Laird Scooby]

Originally Posted by s40t4trowsdale

What does that do? Where is it on the car

It's on the end of the fuel rail and similar to what Alex said, regulates the fuel rail pressure to 3 bar (~45psi) above manifold absolute pressure. When you're idling and the manifold has 20"Hg vacuum (about -10psi) the fuel rail pressure will be ~35psi. At WOT under say 12psi of boost, it will be 57psi.

When trying to start, no vacuum will be present so it will see atmoshperic pressure which it takes as zero for reference so will present 45psi/3bar of fuel pressure.



You won't see the end with the "O" ring on as that will be buried in the fuel rail with the injectors hung on it.