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

[got mung]

Everything works great, it's been dyno'd, driven for a couple days, and on it's first track day, everything goes wrong. I'm going down the back stretch and my headers decide to seperate at the collector and I lose all power instantly. On my way back to the pit area, I notice that my 2d system is still running with my car at an idle. I shut the car off and it shuts off, I turn it on acc and everything fires up again. My dds2 shows that there isn't any flow while it's running. Oh ya, and the priming pump is also running all the time. What broke and how do I fix it?

[Greenv8s]

I think your system has two pressure switches, one on the water manifold (T piece) that controls the pump pressure, and one connected to the engine intake manifold that enables the WI when you come onto boost. If the pressure switch on the water manifold fails, or a wire to it falls off / breaks, the pump would run continuously.

[got mung]

Newest drama is that the wiring is correct. I rewired everything this morning and I believe I found the problem. When the pump is running, there isn't any power going to the priming pump. I think either the pressure switch (806-162) might be shot or the priming pump circuit might have blown. I did notice that the priming pump would click on for a second or two at random. Even if the water injection wasn't activated, the priming pump would still fire up for a second or two. Thinking that the system was loosing pressure, I checked for leaks or kinks and found nothing. The priming pump relay is getting power, but the relay won't activate.

[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

[got mung]

There isn't any power going to the blue wire going to the manifold pressure switch (806-157). I've primed the pump a million times and it still won't stop. I'm curious how the priming pump is activated by the ?manifold switch when it's wired directly into the pressure switch (806-201)? How many wires should have power after the system has been primed?

[Richard L]

The priming of the pump can be independent of the FIA2.

When a successful prime is achieved, the 806-162 pressure switch on the 806-201 manifold will short circuit to ground, stopping the pump from running. Please check this part of the circuit. The grey are is the key to your problem.

Have to adjusted the 806-162 switch at anytime? If the switch is set beyond 10 bar, the pump will never stop.

[Richard L]

One more question, during several of the millon primes, do you see any air bubbles coming out of pump (with water)?

[got mung]

There aren't any bubbles coming out of the pump when I try to prime it up. If I ground the grey wire going to 806-162, the pump should stop right? If it doesn't, what does that mean?

[Richard L]

Interesting,

Can you short the centre pin of the 3-way plug to ground and let me know if the pump stops. Using a spare piece of wire.

[got mung]

So all of the wiring was good, the connection for the pump was kinda shot though. The center pin never made a solid connection. When I moved it back and forth, the pump would shut off. Everything was great other than the priming pump that kept running after. I turned the screw on the water manifold about 1/4 turn and it shut off. Will that make a big difference in the performance of the pump?
On a side note, thanks for your help guys. Richard, you have a great product and your customer support is excellent. I was a little frustrated after I put all this time into wiring and making it look clean just to have it go to hell on me the first track I go to. It worked great for a grand total of a day, 2 if you count the drive to the track. But anyway, great product and I appreciate your help very much.

chris chicoine

[Richard L]

Great, we have managed to trace the source of the problem.

Beyond this, I wil to know if you would like us to send you another pump loom? Sometimes the pin inside plug may be mis-aligned and upon insertion, the mating part may become distorted. Let me know which part of the connection caused the intermittant connection so that I can send you replacement. Fix it good now rather later.

The priming pump activation is done on a separate circuit. It is triggered by the manifold pressure switch (806-157), I think you have found that out.

The 806-157 is factory set at 10psi. 1/4T clockwise from that point will increase the trigger point by ~2.5psi or so. The setting is user determined, so 1.4T clockwise will only delay the trigger point - doesn't degrade the performance of the system.

Richard

[Greenv8s]

Is it possible one of the terminals has 'backed out' of the housing? If so it should be possible to pull that wire right out, check the 'flag' on the side of the terminal that is supposed to latch it into the housing, and simply push it back in.

[got mung]

I went to a local car shop and replaced that plug with a waterproof GM plug. Everything should be good now.