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

[Richard L]

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?

[maskari_gti]

Originally Posted by Richard L

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?

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.

[Richard L]

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.

[maskari_gti]

Originally Posted by Richard L

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.

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.

[Richard L]

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.

[Richard L]

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.

[maskari_gti]

Hello Richard,

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





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.

[Richard L]

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

[maskari_gti]

Originally Posted by Richard L

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

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.

[dave80]

Originally Posted by Richard L

I like to address a common issue on the VW. Interfere causes the gauge to flicker sometimes mistaken as real flow.

I like to make one modification on the green harness (user port). Slice open the vinyl sheath as close to the RJ12 connector as possible. Pick out the white wire and cut it in half.

This wire is not needed on your setup. It sometimes picks up interference from the red and green wire of the Di fuel injector. Let me know how you get on. A picture if possible

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