Hello. Through the years I've found much valuable information here but now I'm stumped.
I have a 2002 Volvo XC70 turbo wagon w 125k miles. A few months back, the car would die out periodically (when it got less than half a tank). I found it to be the fuel pump as it wasn't transferring from one side of the tank to the other, replaced the pump and was fine.
Last week, had run flawlessly. Hot day (100°), experienced loss of power, limped to a stop. No start condition like it ran out of fuel. Towed home. Suspected a faulty fuel pump. Replaced fuel filter. Fuel pump relay checked fine. Tested and got intermittent 12v signal to fuel pump as it should. Checked pump, got two second flow of fuel when I turned key. Cranked engine started continuous flow. There is no fuel pressure regulator at the end of the fuel rail. Now I'm at a dead end. Thoughts please?

 

did you measure the pressure at the rail? I'd suspect the fuel pressure sensor to start. Not sure about the 2002s but on older cars there is both a fuel pump relay and an injector relay. you may want to see if you get a pulse at an injector lead.

 

Fuel may not be the problem.
Double check that you have spark.
Compression OK?