Fuel Pump Hold Pressure
- Disconnect negative battery cable. Disconnect fuel inlet hose at fuel rail. Install fuel pressure gauge to fuel inlet hose and plug fuel pressure gauge outlet hose. Reconnect negative battery cable.
- Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. See Figure . Turn ignition on for 10 seconds to operate fuel pump. Turn ignition off and disconnect jumper wire. Wait 5 minutes and observe fuel pressure. On Miata and 626, fuel pressure should be more than 50 psi (3.5 kg/cm2 ). On Millenia and Protege, fuel pressure should be at least 21 psi (1.5 kg/cm2 ) On MPV, fuel pressure should be at least 25 psi (1.8 kg/cm2 ). On all models, if fuel pressure is not as specified, replace fuel pump.