Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Where is pump located?

Once the failsafe triggered, the idc will reduce as the signal drop below the trigger point.

When you said the pump stopped, was it physically stop or stop flowing fluid?

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

The pump is located in the trunk. It's mounted vertically.

The pump starts (pumping sound starts) and then it goes quiet. I remember clearly in one of my repairs last year, I kept the rear seat unfolded to hear if the pump was working. And I'm 100% sure that once it starts it doesnt go quiet until I take my foot off the pedal.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

When you did the "SYS" test, did it go quiet?

This is most puzzling. The pump is switched on by a relay, either all on or all off. Can you change the relay and see if it cure the problem. It is just a single 4-pin automotive type relay.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

When i did the SYS with FAV harness disconnected, it carried on making pump noise. I couldn't keep the SYS longer than two seconds as you adviced when the FAV harness was connected.

I'll look for a relay to change and see if there's any change.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

If you unplug the red harness, disabling the FAV you can run the pump as long as you like.

I like you a this test if possible, unplug the 4mm hose from the jet and let it spray freeing outside the engine. With the red harness reinstated, run the SYS for 30 seconds, tell me if the fluid flows out freely.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

One more possibility...

If the water filter is clogged, you will get this problem as the fluid started to flow. See if you can purge the system by disconnecting the 6mm from the FAV and observe the flow of the water during "SYS" activation.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Hello Richard,

IVe found this and it's ridiculously expensive. The relay is $40!!

http://i394.photobucket.com/albums/p...pscez7n2xv.jpg

http://i394.photobucket.com/albums/p...psmojx7uij.jpg

I'm catching a flight in few hours so I won't be able to do the cloge test. I'll do it as soon as I'm back though.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

That is this relay made of? They should be no more than 5 dollars!

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I was shocked too. It doesn't have a slot for a fuse too.

I'll look around to buy a normal one once I'm back from my trip and do the cloge test.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Richard is splicing the white wire in half a must for all VW guys? I used to have problems with the false flow readings, but mostly were caused by vibratons I think. Just wondering if there is anything negative from cutting the white wire in the half.

My old false flow thread:http://www.aquamist.co.uk/vbulletin/...ead.php?t=2440

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Cutting the white wire will minimise the interference, one of the cause of interference.

The white wire transmits raw pulses from the flow sensor to the controller and external device. If you are not using a third party ECU, you don't need it. No negative effect

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

So, I can now say that my problem is solved. Big thanks to Richard for assisting me here first of all. You did a great job walking me through various steps of diagnosing the issue. With that, I've learned more about my Aquamist setup. Special thanks to Tensai Tuning in Abu Dhabi for scheduling me in even though they were fully booked.

Things done during the fix in order:

- Visual check for any leaks in general.

• Two leaks on the tank. (Fixed)
• Jet leaking in the TBP. (Replaced with a new 0.8mm Jet)

- Replaced the in tank filter.
- Did a spraying test and found out that the pump is actually pumping.
- Checked spraying after the FAV and turned out to be clogged. So with the aid of air pressure, we managed to free it out. It then sprayed meth from there.
- Checked the soldered wires going to the ECU. All were looking good and in place.

After this, we took the car for a test drive and all worked well. But on my way from the workshop, the same issue came back! So I drove back the following day and had it checked with the following:

- Got a new FAV to check if the problem was there. Issue still exist.
- Finally, started checking the pump and found out the pressure wasn't 160PSI. So, the pressure was then adjusted accordingly.
- Cut the white wire from the USER harness to eliminate false flow. It works 100% now.

Took the car for the final test drive and all is working on well now. Even better than before. No more hiccups. And I mean by that, FS activates from time to time for no obvious reasons.

I'm really happy that the issue is now gone. I can now drive my car happily :D

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Thank for update, happen ending. There was quite a bit of effort on your side. well done. I think a full service every three years should prevent this from happening again.

Juts need to fine tune the WL and WH. Make sure the bars on the gauge does not exceed 6 bars... this stops the WH from triggering.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I really appreciate your swift responses and time spent to get this sorted Richard. I shall do regular servicing every now and then to prevent anything similar from happening.

Just one more question, it's strange what happened to the pump, is this a sign of it dying? I never adjusted it before but how come the pressure was low.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

The pump should last for many years. The drop in pressure could be due to the spring ageing other the years. 1/4 to 1/2T clockwise should address that.

Richard

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

So, the system runs just fine. I logged the car and I can see drop in temperature. I still have timing retardation but that's just -1 to -2 which is acceptable.

Only thing Ive noticed is, the failsafe triggers on the first spraying. But then it runs normally.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

May be a click or two on the WL (counterclockwise) or advance the FSDL a tad.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I'll do that plus I need to adjust the trigger point. I want to make the spraying occur at a lower PSI. How's that possible?

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

You need to lower the WL if you are lowering the threshold.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I was looking at the manual and comparing it with my board. Is the soldering done wrong here?

http://i394.photobucket.com/albums/p...psqzzfsxtz.jpg



http://i394.photobucket.com/albums/p...psiuzh72jh.jpg

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Bump! Any help please? I don't have the amber LED on my gauge no more..

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I am not sure what the problem is, please explain again in more details.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I think that I need to recalibrate my failsafe. Could you please walk me through to accomplish that Richard? I keep getting restricted boost, low MAF readings and not good Intake Air Temps due to having limited power. That's my assumption.

I adjusted the Thres and I believe that failsafe isn't operational no more.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

which way did you adjust the THRES? If you lower the THRES you need to lower the WL.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

I lowerd Thres but I still feel that failsafe isn't 100% as it was.

How can I set a min and max boost? Before, when I used to switch the controller off (FS activates), I used to be able to get 7-8PSI. Now, I got no boost at all. The boost gauge shows 0PSI.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

The system has no control over the boost pressure after failsafe activation. All it does is disconnect the BCV from the ECU.

Under this condition, the boost pressure will be your wastegate pressure.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Hello again,

My car seems to run almost perfectly now. Only thing I notice is lack of cooling affect I used to get in the past. It's a maximum of 10 Degrees Celsius IAT drop. I could't find the issue, frustrated.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

can you check the spray pattern of the jet.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Sorry I didn't quite understand what you mean.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

If the jet is partially clogged, it will show up on a spray pattern test.

Re: Pump starts then stops within a second. MKVI GTI - HFS-4
 

Pull the jets out, jump the board to spray and check the output/pattern. You should be pulling your jets out to clean them once and a while. I pull mine out in Spring (after Winter) and then again towards the end of Summer to clean them out.

As for your failsafes, open the WL and WH all the way to disable the failsafes and see if the problem still happens. If it was your failsafe your car would open the wastegate to dump boost and the car would die off in terms of power.