[s-cars] Moisture Trap vs ECU issues.

[Dave Forgie]

S-gruppees: Late this afternoon, after planting the last of the bedding plants (i.e. keeping the wife off my case), I finally got around to removing my ECU for shipment to Steve Eiche for RS2 software and a VMAP.  When it came to disconnecting the green boost signal tubing, I noticed a drop of brown liquid in the tubing. (Oh, oh).   After killing the OEM crimp on clamp and getting the hose off the MAP tube,  I drained the brown liquid into my hand.  Gas-o-freaking-leen!! WTF??!!  So I go an check the "moisture trap" (mine's an S4 so its out in the engine bay, under the POS cover).  Here I make three discoveries that I need help with:

1.  There is a second OEM clamp on the "outlet" end of the moisture trap (hidden under the cover bracket) that is disturbingly not very tight.  The moisture trap "nipples" do not have any barbs (what's up with that?) and I can just pull the hose off by hand.  On the other end, I had installed a gear clamp years ago and its fine.  NOTE TO SELF: ADD SECOND GEAR CLAMP DUMBY!!

2. The moisture trap has a little direction arrow on it.  In my case, the arrow is pointing back at the engine, not towards the ECU.  This is counter-intuitive.  First thought - Hans and Claus got into the Schnapps at lunch and don't give a flying fraulien when they are installing my moisture trap.  So I phone Sean Douglas (my phone-a-friend in this case). Unfortuately, his is an S6 and the trap is a different design in a different location (see other recent posts).  The question I asked was the arrow important or not.

3.  Okay, so I am concerned that fuel has been getting to my ECU (MAP).  I had previously had a p*ssing match with Mihnea about the nature of the moisture trap.  I said, if it was me, I would have designed the trap with a fuel resistant diaphram so only pressure and not flow (air/fuel mixture to be exact) would be transferred from the intake manifold to the ECU.  (Mihnea disagreed - I ordered a new one to cut open and there were none in NA - still never got the order after 6 months).  Anyway, back at my car,    I figure my moisture trap diaphram is ripped.  So I take the freaking thing off and have a look down one of the nipples.  Hello.  Its a straight through thing.  I can see full dayligh rightt through the nipples.  Forget ripped diaphram or fuel filter media.  There is nothing in there.  Well, except a couple of drops of "moisture", i.e. gasoline.  Hmmmm.

So the questions are:

1.  What am I missing here?  The moisture trap is normally empty and is only supposed to let drops of fuel accumulate (until vacuum draws them back into the intake manifold)????

2.  Is the direction of the arrow important??  I reinstalled the moisture trap but with the arrow pointing towards the ECU.  It made more sense than the other way and, besides, if it is straight through (at least this one), I didn't see that it could be that bad.  The way I have it now its a cone at the inlet end and plate at the outlet end.  This would seem to work as a check valve (of sorts) allowing fuel droplets to be sucked back to the intake manifold easier than pressure pushing them to the ECU (the way I found it, boost could easily push droplets down the line).

Any assistance will be appreciated.   Oh, ya, how does one retreive an ECU hold down screw that gets dropped into the abyss of the footwell.  I would use a magnet to troll for it if it wasn't for the (spare) ECU that I installed (in place of mine).

Thanks in Advance,  I am confident that somebody will have answers to these questions.

Dave F.






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