Fuel feed pressure Volvo d12

Could be injectors cups check valves, fuel filter housing very common or maybe accessory drive is messed up how was the shaft in the old pump that u pulled out.

 

Like nasriza said its most likely accesorie drive or filter housing. If its filter housing change it before winter it gets worse when its cold don't ask me how i know

 

If the shaft on the old pump was worn out than I would consider changing accessory drive I always change them as a set start with filter housing they are known to make a lot of problems as well

 

Before you change the accessory drive, try the fuel pressure relief valve. It may be stuck open or the spring is weak if it's original. It's at the front of the head on the driver's side next to the valve cover emissions sticker. There's a banjo bolt with a fuel line screwed into the head and the valve screws into the top of the banjo bolt. For around $30 and 3 minutes, it's easier than going straight for the accessory drive. The part number is 21697342.

 

I changed fuel pump, fuel filter housing and accessory drive in march and i got same code again month ago, first once a week and later every day. I changed fuel return valve and everything is fine now. Part is $55