Fuel Tank - Difficulty Filling
911 (996)5/99 2015
Binder - 2, Fuel & Exhaust
Date: 8-12-99
Fuel Tank Hose Modification
Vehicle Type:
911 Carrera (996), 911 Carrera 4 (996)
Model Year:
As of 1999 (X)
Concern:
1. Difficulty filling fuel tank.
2. Running out of fuel due to incorrect fuel gauge reading.
Information:
1. Difficulty filling the fuel tank can occur if the flexible fuel hoses in the fuel tank obstruct the inner flap of the fuel filler neck.
2. Incorrect fuel gauge readings can also be caused by the flexible fuel hoses in the fuel tank, should they interfere with the travel of the fuel sending unit arm and/or float.
When addressing complaints of "difficulty fueling" or "running out of fuel", the routing of the flexible fuel hoses in the fuel tank must be modified. Additionally, on the 911 Carrera 4, it must be ensured that the jet pump end caps are in place and the connections for the two jet pump lines are properly connected.
Warning!
There is danger of fire and injury when working with fuel! Always observe all general safety regulations for working on the fuel system! Wear protective gloves!
Work Procedure:
Performing fuel hose modification.
- Mark the position of the fuel sender union nut before removing. Remove union nut and fuel sending unit.
- Carrera 4 only: Confirm the integrity of the jet pumps by removing and inspecting, ensuring they are completely intact. Replace the jet pumps if the end caps have come loose. Ensure jet pump lines are fully connected and snapped into place upon completion.
- Ensure the inner filler neck flap moves freely. Affix the two flexible hoses in the fuel tank exactly as shown in Figure 1, using two tie-straps.
- Install fuel sending unit and union nut. Ensure the arrow on the fuel sending unit is perfectly aligned with the middle mark on the fuel tank. Tighten union nut one additional rib further than its previously installed position. (Use the markings made previously for reference.) See the 911 Carrera (996) Technical Manual, page 20-7.
Note:
If ever a fuel level sending unit is replaced, or if it suspected that the fuel system is out of calibration, the method of calibration is crucial. When performing a fuel system calibration on the Carrera 4, it is important to ensure the fuel tank is completely empty of fuel before the calibrated amount of fuel is added. This must be confirmed with a visual inspection through the upper tank opening Do not rely upon the jet pumps alone, or the tank may be incorrectly calibrated. See the 911 Carrera (996) Technical Manual.
Working Time:
Labor Operation Time Description
20 15 01 00 110 TU Checking 911 fuel hoses at fuel sender
Includes: Removing and installing fuel level sensor, calibrating
fuel system if necessary.
Literature:
911 Carrera (996) Technical Manual, Group 2, sections:
20 66 19 - Removing and installing fuel pump, pages 20-7 20-9
20 15 D1 - Calibrating fuel level sensor system, page 20-7
911 Carrera 4 (996) Technical Manual, Group 2, sections:
20 66 19 - Removing and installing fuel pump, pages 20-101 - 20-109
20 15 D1 - Calibrating fuel level sensor system, page 20-115