04 STi WI on all the time ::FIXED::

[Richard L]

I think there were two things are happening here.

1) During the track run, some air must have gone into the water delivery line to the pump, if the system was not build pressure, the pump will run continuously. Unfortunately, the trapped air cannot escape until the system is primed. You need to prime the system again to ensure the pressure is built up (pump stops after that)

2) The priming pump is trtiggered by the manifold pressure switch (806-157). You can simulate the condition by pulling one of the wire off the 806-157 pressure switch. Ensure the engine is in idle so only a small amount of water is injected into the engine - WI duty cycle is low at idle.

Once the blue wire from the FIA2 is pull from the pressure switch, the priming pump should start immediately.

Please let me know how you get on. It is advisable to put some baffles in the tank to stop the water from sloshing about. Or, use a small narrow-neck collector tank below the main tank.

Richard