WARNING: Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components.

Remove hot-air guide at left rear of engine compartment. Disconnect fuel return line from fuel distributor. See Fig 1 . Connect fuel pressure gauge. Catch any spilled fuel using a shop rag.
Disconnect DME relay from fuse/relay block. Jump terminals No. 30 and 87b together. See Fig 1 . Fuel pump should operate at specified pressure. See FUEL PUMP PERFORMANCE .

CAUTION: DO NOT pinch polyamide fuel pipes closed for any reason. Polyamide pipes cannot be bent or clamped without causing permanent damage. DO NOT allow sealing ball to fall out when removing cap nut.

FUEL PUMP PERFORMANCE

Application

Pressure psi (kg/cm² )

Volume In 30 Sec. Pts. (L)

All Models

⁽¹⁾ 52-58 (3.6-4.0)

1.8 (.85)

⁽¹⁾	Unregulated pressure (no vacuum applied to pressure regulator). Regulated pressure (vacuum applied to pressure regulator) is 45-51 psi (3.1-3.5 kg/cm² ).

Fig 1: Testing Fuel Pump Pressure & Volume

Courtesy of PORSCHE OF NORTH AMERICA, INC.

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.

Safety Warning

Fuel Pressure

Use the Manual With the Right Hardware

When to See a Mechanic