Help with 2341 fault code

[UrS4boy]

Already replaced that part and rechecked the other day.

Too bad. That would be easy. Now air from the filler cap during the boost leak test most likely means the valve seals.

Guides show here as the yellow/bronze bits in the second photo. Seals are above. Item 17, PN 027109675 (7 mm) in the diagram.

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[andyg plym]

Is there anything else it could be ? It doesn't smoke and my mate who did a boost leak test with me last time said the air was coming through the oil cap then as well and this was ages ago.
Noticed some yellow scum in the pcv valve when I quickly swapped a jubilee clip this morning.
Could a blocked pcv system cause these symptoms too ?
Thanks again

[andyg plym]

So do we think these 2 issues are related ?

This morning it started on the key and was fine for around a minute then started idling roughly.
I keep coming back to exhaust manifold or gasket, something that's cold then expands when warming up.
Feel so close to this

[mike74]

Doesn't the car need more fuel at idle when cold compared to when hot? (to stop it stalling)
Next time it does this, whip off the vacuum/boost pipe that connects to the FPR (and block the pipe) and connect the FPR directly to a foot pump. Stick in around 14 psi/1 bar and see if the idle improves any.
IF it improves then you have a fuel supply/pressure issue

[andyg plym]

Cheers mike interesting theory, I believe it's running too rich on idle.
I did start up and whilst it was hunting/missing pulled the hose of the fpr to see if any difference but nothing. Didn't have a foot pump too hand unfortunately !
Also whilst it was cold and hunting I disconnected the lambda just to see but this too made no change to the lambda but does when warm

[mike74]

It may very well still be a dodgy FPR that's to blame, it might be sticking closed slightly and causing it to overfuel. For the sake of 20 quid a fuel pressure gauge temporarily hooked up could tell you a lot about what's going on, one way or another

[Rusty]

I'd remove the PCV system gubbins round the back of the head and connect the N80 fuel tank breather direct to the head and remove the T pipe and one-way valve.

The air coming out of the oil filler cap should not happen with the inlet hose oil feed removed and plugged. If it still happens, then you ahve an issue with the one-way valve or that whole area, so again, best to just ditch the lot and simplify things, to give you a starting point.

I have not had the OE breather system for a few years and it's a vast improvement for track days.

[andyg plym]

Guys your all going to love me....not check out my manifold :

http://www.s2forum.com/forum/showthread.php?t=43028&highlight=Manifold

This is the one I bought when I did my conversion, as it was cheap it was worth the punt .
Completely forgot about the internal cracks, however there are none visible on inspection or at least on the outside.
Maybe it's finally given up the ghost and as the engine warms any cracks may close up ?

[UrS4boy]

Completely forgot about the internal cracks, however there are none visible on inspection or at least on the outside.
Maybe it's finally given up the ghost and as the engine warms any cracks may close up ?

Or maybe it has spalled some chunks of cast iron that have damaged the blades of the hot side of the turbo?

[andyg plym]

Hmmm hope not obviously. I checked the cold side the other nite and all was well.
Turbo is under 2 years old

[andyg plym]

Fixed it !! It was the maf....never had a fault code for it though..
It appears to be damaged will post pics later

[UrS4boy]

Fixed it !! It was the maf....never had a fault code for it though.. It appears to be damaged will post pics later

Congrats. And yes, please post photos soon so we can see what the issue was and add the info to the MAF archives.

[andyg plym]

image.jpg

Note the damaged brown housing but also the right hand wire has a burn mark on it towards the top, I may have damaged it when putting the airbox back in and it being poked up against the tube on the top of the waste gate
Gutted I never saw it sooner, wires looked ok when I checked but obviously didn't see the wood for the trees
Mystery how I never got a fault code, if I disconnected it whilst idleing it would cut out as you'd expect

[UrS4boy]

Holding Relay and MAF wire burn-off info

Note the damaged brown housing but also the right hand wire has a burn mark on it towards the top, I may have damaged it when putting the airbox back in and it being poked up against the tube on the top of the waste gate. Gutted I never saw it sooner, wires looked ok when I checked but obviously didn't see the wood for the trees. Mystery how I never got a fault code, if I disconnected it whilst idleing it would cut out as you'd expect

Not sure why that crack would cause a problem. My guess is you could repair that with some epoxy, smoothing it out, so as to not distrupt airflow and it would work fine.

There is a brown spot on the wire because the Holding Relay in the ECU puts the hot wire through a burn-off cycle everytime the engine has run for more than a minium time/RPM and then shut off. I would clean that spot with some MAF cleaner and Q-tip. I think there was no MAF fault code per se because the MAF is basically fine, if slightly blemished at this point.

Holding Relay info: http://forums.quattroworld.com/s4s6/msgs/102009.phtml

[driftin jo]

[ATTACH]50953[/ATTACH]

Note the damaged brown housing but also the right hand wire has a burn mark on it towards the top, I may have damaged it when putting the airbox back in and it being poked up against the tube on the top of the waste gate
Gutted I never saw it sooner, wires looked ok when I checked but obviously didn't see the wood for the trees
Mystery how I never got a fault code, if I disconnected it whilst idleing it would cut out as you'd expect

Actually it shouldn't cut out if you disconnect the MAF, the ECU should revert to using TPS for ref for basic fuelling.