How do I relieve fuel pressure

Tiny
TIMINMICHIGAN
  • MEMBER
  • 2000 MERCURY MYSTIQUE
  • 2.0L
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 150,000 MILES
How do I relieve fuel pressure for my 2000 mercury mystique, 2.0l? It is the returnless fuel system, with a fuel rail (aka Fuel injector) pressure sensor. There is no Schrader valve or other release port.

The Chilton and other manuals are based on the older fuel system design.

When I remove the FUEL PUMP FUSE (15amp - the only one - fuse#9) and the FUEL PUMP RELAY (relay #1), the car still continues to run, even 3 minutes later. The relay I understand. In newer systems, if the oil pressure switch detects pressure, it overrides the relay.

Can the shut-off fuel switch be used? Where is the electrical connector. OR, can I use another method to relief fuel pressure?

Tim

Thursday, April 30th, 2015 AT 5:30 PM

1 Reply

Tiny
CARADIODOC
  • MECHANIC
  • 33,741 POSTS
If an oil pressure switch is keeping the pump running, just unplug the sending unit. The fuel pump will still run for about one second after turning on the ignition switch.

Why are you trying to relieve the fuel pressure?
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Thursday, April 30th, 2015 AT 7:28 PM

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