Bryon, the return fuel pressure regulator is located on the rear of engine head with a hose connected to one end and other end connect
To engine head. My suggestion before replacement of regulator disconnect hose on the end of regulator and connect a clear plastic hose
to the male end and put other end of plastic into a gallon container have someone start engine and watch the diesel fuel going into the
Fuel container. What you should be seeing is a stream of clear fuel within air bubbles present. Run engine at steady speed and not speed up and down for two minutes at idle than half speed than 3-4 speed again hold at steady rpms doing test. Again your for stream of clear fuel
with no air bubbles., ufnoaue bubbles present there is nothing wrong with return fuel pressure regulator. Is you see lot of air bubbles than your problem is entry of air on suction side of your fuel transfer pump to fuel tank.where your problem is located causing low fuel pressure, hard starting and low power. Dave Atherton Rerured Cat Mechanic
