Fuel Pressure

NOTE: All models use in-tank fuel pump. Fuel pump contains internal relief valve and check valve.

Ensure battery is fully charged and ignition is off. Disconnect negative battery cable. Disconnect electrical connector from cold start injector (if equipped).
Note location of fuel pressure gauge installation. See Fig 1 and Fig 2. Place container under cold start injector pipe, delivery pipe or fuel filter. Cover union bolt with shop towel. Slowly loosen union bolt to relieve fuel pressure.
Remove union bolt and gaskets. Install Fuel Pressure Gauge (SST 09268-45012) using NEW gaskets. See Fig 1 and Fig 2. Tighten union bolt. Reconnect negative battery cable.
Install jumper wire between +B and FP terminals of data link connector. See Figure and Figure. Data link connector is located below driver's seat.
On all models, turn ignition on and note fuel pressure. Fuel pressure should be within specification. See FUEL PUMP PERFORMANCE table.
If fuel pressure exceeds specification, replace fuel pressure regulator. If fuel pressure is less than specified, check for defective fuel lines, connections, fuel pump, fuel filter or fuel pressure regulator.
Remove jumper wire from data link connector. Start engine and allow to idle. Disconnect and plug vacuum line at fuel pressure regulator. Note fuel pressure.
Reconnect vacuum hose on fuel pressure regulator and note fuel pressure. Fuel pressure should be within specification. See appropriate REGULATED FUEL PRESSURE table.
If fuel pressure is not within specification, check for defective vacuum hose or fuel pressure regulator. Shut engine off and note fuel pressure.
Fuel pressure should hold at least 21 psi (1.5 kg/cm² ) for a minimum of 5 minutes. If fuel pressure does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
Disconnect negative battery cable. Remove fuel pressure gauge. Reinstall union bolt using NEW gaskets. Tighten union bolt. Install cold start injector electrical connector (if equipped). Install negative battery cable.

NOTE: For more information on checking fuel injectors and other fuel sub-systems, see SYSTEM/COMPONENT TESTS article.

FUEL PUMP PERFORMANCE

Application

⁽¹⁾ psi (kg/cm² )

4-Cylinder

Supercharged

33-40 (2.3-2.8)

Non-Supercharged

38-44 (2.7-3.1)

⁽¹⁾	Check fuel pressure with jumper wire installed between data link connector +B and FP terminals, ignition on and engine off.

REGULATED FUEL PRESSURE

Application Type	At Idle W/Vacuum	At Idle W/O Vacuum
Supercharged	24-31 (1.7-2.2)	33-40 (2.3-2.8)
Non-Supercharged	30-36 (2.1-2.5)	38-44 (2.7-3.1)

Fig 1: Installing Fuel Pressure Gauge (Supercharged)

Fig 2: Installing Fuel Pressure Gauge (Non-Supercharged)