A Schrader valve is provided on these fuel systems, in order to conveniently test or release the system pressure. A fuel pressure gauge and adapter will be necessary to connect the gauge to the fitting. Most of the MFI systems utilize a service valve on one end of the fuel rail assembly. The CMFI system covered here uses a valve located on the inlet pipe fitting, immediately before it enters the CMFI assembly (towards the rear of the engine)
- Before servicing the vehicle, refer to the Precautions section.
- Turn the ignition OFF .
- Disconnect the negative battery cable.
- Loosen the fuel filler cap in order to relieve the fuel tank vapor pressure.
- Connect a fuel pressure gauge to the fuel pressure valve/fitting.
- Wrap a shop towel around the fitting while connecting the gauge in order to avoid spillage.
- Install the bleed hose of the gauge into an approved container.
- Open the valve on the gauge to bleed the system pressure.
The fuel connections are now safe for servicing. Drain any fuel remaining in the gauge into an approved container.