Failsafe at Full Throttle

[Canonshooter]

I've had the system for six years, still works well!

However, recently I noticed that if I go full throttle, the bars drop and it goes into failsafe. If I'm on it aggressively but not at full throttle, I get 5 to 6 bars and it holds. As soon as I go full throttle, bars drop back to 3 or 4 and it trips failsafe.

Any advice on where to start looking is appreciated!

[Richard L]

It appears there is a partial clog somewhere along the delivery line. The first item to check is the in-tank filter.

Post you set up just as, system, jet size and trigger point etc. As much as you can manage. the more info the better. Or just post an image of the controller, top and bottom.

[Canonshooter]

Originally Posted by Richard L

It appears there is a partial clog somewhere along the delivery line. The first item to check is the in-tank filter.

Richard, that is indeed what I plan to do this weekend. I've used only bottled distilled water mixed 50/50 with HEET gas line anti-freeze as my "boost juice" for the last 5 years, being careful not to let any debris get in the tank.

FWIW, I'm using my windshield washer reservoir to hold the water/meth mix. The only downside so far is that boost juice evaporates too quickly when sprayed on the windshield and leaves streaks. That said, perhaps some dirt got in the tank from the washer system so I'll get a good look at the screen.

Originally Posted by Richard L

Post you set up just as, system, jet size and trigger point etc. As much as you can manage. the more info the better. Or just post an image of the controller, top and bottom.

Will do. One way or the other I will post again after I check the tank screen. If the problem persists, I will also post a video of the gauge behavior when going into boost and when it trips failsafe.

Thanks for your help with this!

[Richard L]

Six-year service without any maintenance is pretty impressive.

[Richard L]

Post a picture of the tank arrangement.

[Canonshooter]

The issue appears to be resolved!

I checked the flow out of the tank by disconnecting the line at the pump inlet, and it promptly emptied in my driveway. ;-/

I went for a test drive applied enough throttle to get into full boost, at which point I noticed that all bars lit on the gauge. I turned the SC trimmer back a notch and got it down to 5 bars at full boost, partial throttle. Finally I went WOT in second gear through to a shift into third (4EAT tranny), the gauge remained at 5 bars with no tripping of the failsafe. So for now (after 6+ years of operation!), all remains good!

As per Richard's request, some photos;



Washer reservoir removed. Top float is an extra one I installed at mid tank, the lower is part of the HFS3 kit.




Outlet to pump.




Tank and pump installed, high pressure line goes through aluminum bar that serves as the mount for my driving lights.




Though the pump is reasonably protected, I made a splash guard for it out of an plastic food storage container.




FAV installed under hood on strut tower.




One nozzle is installed in my Perrin TMIC...




...another installed in the splitter to spray the exterior of the TMIC.




Gauge install. The switch on the shifter locks the clutch pack in the VTD center differential.




A recent shot of my 2007 Forester XT.

[Canonshooter]

Update

A day later the issue has returned, exactly the same as before. I removed the FAV assembly and removed the flow turbine sensor, finding that it initially spins when I blow through it but then binds. This is exactly what I'm seeing on the gauge, so I'm assuming that I will need to replace the flow turbine. :-(

I have not yet done the flow test as I need to remove the intercooler to get to that jet - and removing the intercooler in my car is a MAJOR pain in the arse! So before I do, I'm going to get the fittings to relocate that jet to the top of the TMIC where I can get to it without having to remove the intercooler, then run the test to confirm the issue.

For my normal driving needs, the system still runs fine. It seems the flow turbine only binds under certain conditions but I need to get to the bottom if it nonetheless.

[Richard L]

The flow sensor is the first generation design. The newer one comes with an 100um inline disc filter.


Still very impressive with the installation, the pump is still alive, to my surprise. The minute amount condensation from the warming air inside the pump head will cause the bearings to rust over time. But in your case, it does not. Your protection cover works really well.

[Canonshooter]

Originally Posted by Richard L

Still very impressive with the installation, the pump is still alive, to my surprise. The minute amount condensation from the warming air inside the pump head will cause the bearings to rust over time.

Richard, what is the typical mode of pump failure? Does it just stop working or does start off as an intermittent issue?

BTW, I took the flow sensor out again and it seems to spin OK, but also seems to vibrate like it's out of balance. I put it back in "backwards" (reversed flow) and it actually seems much better, giving smoother readings, but still stops reading flow at full throttle.

I'll pull the TMIC and do a flow test next weekend.

[Richard L]

It will be intermittent.

Here is a picture of a seized bearing: