Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1987 Porsche 944 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Fuel Pressure
- Locate fuel pipe cap nut at end of fuel rail (left side on 911 Carrera). Remove cap being careful that sealing ball does not fall out. Connect a Test Pressure Gauge (P 378).
- Start engine and maintain idle speed. Pressure gauge should show 29.4 psi (2.06 kg/cm2 ). Disconnect vacuum line at pressure regulator. Pressure gauge should show 33.8-39.7 psi (2.37-2.78 kg/cm2 ).
- Pinch fuel return line of pressure regulator. Pressure gauge should show a minimum of 59.0 psi (4.13 kg/cm2 ). If fuel pump does not meet specifications, check fuel filter or replace fuel pump and retest.
- If engine will not start, check fuse No. 2. If good, remove DME relay (911 Carrera), or fuel pump relay "U" (924S and 944) and bridge terminals No. 30 and 87b. Pressure gauge should show 33.8-39.7 psi (2.37-2.78 kg/cm2 ).
Factory Service Tools
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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.