Be Safe!

Most accidents occur because people don't anticipate all the things that can go wrong. Working with the fuel system is pretty straight forward but inherently dangerous. So think about what might go wrong and be ready for it. If you don't have a small fire extinguisher, get one. If you do, have it ready. Just a little bit of planning is the difference in an incident and a disaster.

Basic Pressure Testing

Once the engine is cool, start by removing the fuel rail test port cap and the small ball (inside the cap). Its best to counter hold the fuel rail so prevent damage to the rail or the injector seals. You may want to have a small rag under the test port to catch any residual fuel, if the car has sat over night without the engine running this will be as little as a few drops or as much as a 1/4 cup. Assemble the guage hose and attach the fuel pressure tester to the test port.

Use the jumper wire to enable the fuel pump and observe the pressure reading. If you are troubleshooting a no-start problem, you might choose to skip the jumper and just use the ignition key. When the engine begins to turn over, you should see the the pressure jump to an acceptable reading. Be watchful fo rleaks. It should hold that reading for several seconds after the pump/ignition is off (see leak down portion of the reference table, below).

To safely pressurize the system and ensure there are no leaks, jumper the DME relay (pins 37 & 87b) as shown above. This will enable the fuel pump and you can then verify or correct leaks.

Delivery Rate (capacity) Testing or emptying of Fuel Tank

Note: A good fuel pump will fill a small container very quickly so have an adequate container ready to catch the fuel. Use the jumper wire as described above and the clear drain hose.

Reference Test Values.

Torque setting for re-installation of the test port cap = 16 ft/lbs