Troubleshooting Troubleshooting – Fuel System – 2.5L NA Estimated reading: 2 minutes Contributors Overview This troubleshooting guide is designed to help identify and repair fuel system issues specific to the Porsche 944 3.0L S2 (1989–1991). Proper fuel system maintenance is critical for ensuring optimal performance, fuel efficiency, and safety. This procedure addresses common symptoms such as excessive fuel consumption and strong fuel smells in the passenger compartment, tailored for the late-model 944 S2 with alloy control arms. Troubleshooting – Fuel System The following guide addresses two primary symptoms for the Porsche 944 3.0L S2 fuel system: excessive fuel consumption and strong fuel smell in the passenger compartment. Excessive Fuel Consumption Possible Causes Checks Procedure Dirty Air Filter Check / Change Air Filter N/A Bad O2 Sensor Check sensor and replace if necessary FUEL-18 Poor Ignition System Function Check the condition of the distributor cap and rotor. Check the condition of the spark plugs and spark plug wires. IGN-04 Strong Fuel Smell In Passenger’s Compartment Possible Causes Checks Procedure Fuel Level Sender Gasket Locate the fuel level sender and check the condition of the gasket around the sender cap. If it appears hard/brittle, remove the sender and replace the gasket. The part number for the gasket is 944-201-327-00. ELECT-13 Fuel Tank Ventilation System The fuel tank has a ventilation system to prevent pressure buildup by removing fuel vapor. The system includes hoses running from the tank along the bottom of the vehicle on the right-hand side, into the engine compartment, along the back of the firewall, to a charcoal filter canister in the left fender well (remove the interior fender well cover to locate canister). Check for loose, cut, or leaking fuel lines, or a split/leaking charcoal canister. N/A Fuel Filler or Fuel Reservoir System Leak Check rubber hoses and sleeves in the fuel filler and reservoir system for holes or loose hose clamps. These components are located in the rear hatch area behind the carpet on the fuel filler side and behind the paneling on the inside of the roof pillar. A common issue is a stuck ventilation valve (#17 in the Late Fuel Diagram), part number 928 201 083 02, which may cause a “whooshing” sound when removing the fuel filler cap. A leaking fuel cap gasket (part number 944 201 553 00) or an elongated fuel filler neck (part number 931 201 281 02) can also cause fuel smells. N/A Sources Clark’s Garage Pelican Parts Porsche 944 Workshop Manuals YouTube Tagged:Fuel System Troubleshooting Troubleshooting – Fuel System – 2.5L NA - PreviousTroubleshooting – Engine – 2.5L NANext - Troubleshooting – Fuel System – 2.5L NATroubleshooting – Manual Transmission – 2.5L NA
