Hello Wayne,

The new fuel pumps supplied by the aftermarket for the last 15 years have check valves I don't trust. And part of the job of the check valves is to control fuel pressure. In comparison to the check valves used in the Volvo original mechanical fuel pumps, the new ones are flimsy and don't have springs. So whenever I use one I like to check the dead head and operating fuel pressure after I install one. I have seen this style of check valve being capable of 7 lbs and that is too much. And overflowing float bowls is not what you want over a hot exhaust manifold.

HOWEVER, I HAVE NOT ENCOUNTERED HIGH FUEL PRESSURE PROBLEMS WITH THE LATEST BATCH OF FUEL PUMPS SOURCED THROUGH PPS (Professional Parts of Sweden), even though they do have the flimsy style of check valves.

Although I did have to replace a PPS fuel pump under warranty because the outlet tube was loose and leaking fuel. And that's when I noticed that their tubes aren't cast into the upper housing, but GLUED IN PLACE!

Post a picture of your existing mechanical fuel pump as it might be one of the older ones that is worth rebuilding.


--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com