Differential Pressure Regulator Fuel Pressure
- Connect Fuel Pressure Tester (VW 1318) as previously described in FUEL SYSTEM PRESSURE. See Figure . Close fuel pressure valve. Relieve pressure. Disconnect harness connector at differential pressure regulator. Using Remote Control (US 4480/3), as previously connected in step 2) of FUEL SYSTEM PRESSURE, energize fuel pump and note fuel pressure. Fuel pressure should be 4.3-7.3 psi. (.3-.5 kg.cm2 ) less than fuel pressure noted in step 3) of FUEL SYSTEM PRESSURE.
- If not, remove small diameter fuel line from fuel pressure regulator and place in container. Plug fuel line opening on fuel pressure regulator.
- Using remote control, energize fuel pump for one minute and measure quantity of fuel in container. Fuel captured in container should be 130-150 ccs. If fuel quantity is less, replace fuel pressure regulator. Reconnect fuel line to fuel pressure regulator.
- Disconnect ignition coil wire and ground. Disconnect CTS harness connector and insert 15,000-ohm side of Bridge Adapter (VW 1490) into CTS harness connector. See Figure .
- Crank engine for about 5 seconds and leave ignition on. Using remote control, energize fuel pump and note reading on fuel pressure gauge. Fuel pressure must be 18.9-23.2 psi (1.4-1.6 kg/cm2 ) less than fuel pressure noted in step 3) of FUEL SYSTEM PRESSURE.
- If not, replace differential pressure regulator. If difference between fuel pressures is as specified, check wiring harness and ECU.