1987 Merkur XR4Ti AutomaticFACTORY OEM SERVICE PROCEDURE

Fuel Pressure

CAUTION: Constant fuel pressure is maintained in fuel lines and component parts at all times. Relieve pressure before attempting to open system for testing. Do not allow fuel to flow onto engine or electrical parts or allow an open flame in area while testing fuel system components.
  1. Connect EFI Fuel Pressure Gauge (T80L 9974 A) and Adapter Hose (T85L 9974 A) to the Schrader valve on the fuel supply manifold. Start the engine. If the engine will not start, remove fuel pump relay from fuse panel. Connect a jumper wire from relay terminals No. 87 to No. 30. See Fig 1 .
  2. Check the reading on the pressure gauge. Fuel pressure should be 35-45 psi (2.4-3.0 kg/cm2 ).
  3. Insert the test volume hose in a graduated container and open the flow control valve for 10 seconds. Fuel pump should deliver 7.5 ounces in 10 seconds. If so, the volume test is within specifications.
  4. Disconnect the jumper wire. Observe the pressure gauge. If the pressure holds at a minimum of 30 psi (2.0 kg/cm2 ) the system is holding pressure. Reinstall fuel pump relay.
Fig 1: Identification of Relay Terminals
G62295
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.