fuel pressure regulator testing
Logistics Pro
Joined: Jan 2002
Posts: 4,907
Likes: 39
From: suburban atlanta
Two things worth mentioning: 1) if you pull the vacuum hose from the regulator, and it leaks fuel, it is broken. 2) you can get a (~$30) pressure gauge that will connect to the schrader valve on the fuel rail to test the regulator. The one I got has a releif valve and relief hose to collect the fuel that ends up in the hose connected to the rail.
Vacuum gauges indicate vacuum. I suppose you could tee into the regulator vacuum connection if you want to see the vacuum applied to the regulator. I think the returnless systems may not have a regulator, but would only bet Your paycheck on that...
tom
Vacuum gauges indicate vacuum. I suppose you could tee into the regulator vacuum connection if you want to see the vacuum applied to the regulator. I think the returnless systems may not have a regulator, but would only bet Your paycheck on that...
tom
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
Fuel Pressure Regulator Test
Fuel Pressure Regulator Test
This test checks the operation of the fuel pressure regulator to make sure it changes line pressure in response to changes in engine vacuum. This is necessary to maintain the proper operating pressure behind the injectors and to compensate for changes in engine load.
With the engine running, disconnect the vacuum hose from the pressure regulator. As a rule, fuel system pressure should increase...with the line disconnected. No change would indicate a faulty pressure regulator, or a leaky or plugged vacuum line.
If the diaphragm inside the regulator is leaking, engine vacuum will suck raw fuel into the intake manifold through the vacuum hose (look for fuel inside the hose). Source
This test checks the operation of the fuel pressure regulator to make sure it changes line pressure in response to changes in engine vacuum. This is necessary to maintain the proper operating pressure behind the injectors and to compensate for changes in engine load.
With the engine running, disconnect the vacuum hose from the pressure regulator. As a rule, fuel system pressure should increase...with the line disconnected. No change would indicate a faulty pressure regulator, or a leaky or plugged vacuum line.
If the diaphragm inside the regulator is leaking, engine vacuum will suck raw fuel into the intake manifold through the vacuum hose (look for fuel inside the hose). Source
http://fords.kilonet.org/ken00/FuelPressureTesting.doc
