1997 Ford F150 fuel pressure

1997 FORD F-150
147,000 MILES • V8 • 4WD • AUTOMATIC
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SGARBEL
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I have just tested the fuel pressure on my pick up. The pressure should be 55psi when ignition is on and 55psi when vehicle is running.

Currently when the key is in on position the pressure is at 32 psi. When running it is 32 psi.

When i rev the engine the gage rises to about 37-38 psi. 5 psi increas.

I also removed the fuel regulator vacuum line it jumped about 5 psi.

Note: i pinched the the fuel return line and the pressure jumped to 60-70 psi depending on how long i pinched the line (up to 5 seconds). Also, when the vehicle sits for about 20 min with the pressure gage still hooked up the pressure rises to 38psi.
Sep 9, 2010 at 11:38 AM
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RASMATAZ
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Disconnecting the vac hose on the regulator should cause pressure to increase about 8-12psi check the vac hose if its leaking/plugged if okay could be the injectors are leaking dropping the pressure, also the fuel pump could be on its way out
Sep 9, 2010 at 12:15 PM
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SGARBEL
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[quote:415a6cd23e="rasmataz"]Disconnecting the vac hose on the regulator should cause pressure to increase about 8-12psi check the vac hose if its leaking/plugged if okay could be the injectors are leaking dropping the pressure, also the fuel pump could be on its way out[/quote:415a6cd23e]

When i hooked up the OBD2 code reader it pulled up cylinder misfire on #1 and 4 and also system too lean on Bank 1 and 2. I have already replaced the fuel filter. I was thinking about replacing the fuel regulator. When the vehicle sits for about 20 min with out the key in the ignition the pressure will rise to 38 psi.
Sep 9, 2010 at 12:24 PM
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