'04 V70 FWD Turbo 2.5 Fuel Pump issue- check valve?

[cypilot]

We recently upgraded to an '04 V70 2.5 turbo automatic for one of our college-age kids. 135k miles, great shape. Lotta new OEM parts, inc virtually every front suspension component. This was a well-maintained car.

We've had a myriad of Volvos and we do all our own work. This car replaced a '98 V70 FWD non-turbo that we bought when my son was 13- we wrenched on it until he had a passable mechanical knowledge, then he drove it for 7 years. At 235k it needed a clutch, but what it really needed was a new home and a new 13 year-old to love it. We also have an '08 V30, and just sold 2 V50's last year.

So we bought this '04 to get the 20 year old thru college.

Question for the educated P2 masses:
Is there a check valve after the fuel pump to keep pressure in the line? We're having to crank quite a while before starting when the tank is below 1/4 tank. I recall in the 240's that this was a sign of the pre-pump failing, and allowing fuel to flow back into the tank between starts. With the P2 only having one pump, I suspect it's dead or dying, but if there's a check valve I'd far prefer to replace that to see if it fixes the problem before pulling the pump out and replacing it.

Notes:
1) Plenty of battery juice- I installed an H8/Series 31 1000CCA battery to deal with long periods of sitting as well as Iowa winter temps of down to -20F. It's tested perfect.
2) No codes except a fuel pressure sensor code which, once cleared, hasnt' come back.
3) The car always starts, and starts strong. It just takes several seconds of cranking if the tank is below 1/4 tank (and yes, keeping fuel above 1/4 tank would make this easy, but....have you ever met a 20 year old male college kid?- he's going to prioritize beer over fuel for his limited resources every day).

Thanks in advance.

[jonesg]

that was a split year, establish whether it has PEM or pump return line system.
A fuel pressure sensor on the end of the rail indicates the PEM, usually on top of the tank.
A schraeder valve on the end of the rail means no PEM but you can read fuel pressure with a gauge.
PEM reports fuel pressure to the ecm and can be read with a scanner.

key on prime should be around 55psi, idling 45psi.
i would confirm fuel pressure first.

[cypilot]

Fantastic. that's what I needed to know. Thanks!