17705 pressure drop. 1 fault, LOTS replaced but still there.

[Craig1.8t]

1.8t AUM.

This is the only fault code I am getting, I have tried pretty much everything, in fact too much to remember in one go..

To get to basics I have no split pipes (boost and vacuum) pcv system is fine throttle body is clean and alligned dv is fine

Car has poor performance at low rpm and jerky, but varies on how bad it is mostly its only just noticeable other times an embarrassment to drive, if I drive the car hard and then come to a stand still engine sometimes idles rough and drives rough for about 10 mins and smooths out but not 100% I was told it was the map so I changed ecu to a standard one and it's still same.

It's a nightmare! Anyone got any ideas? I have vag com, and all measured values seem to be ok.

Thanks

 

[camscockle20vT]

Not sure what the code is but id say if your 100% its not a split pipe then its likely to be the fuel pump dying, i mean it could be anything like a dodgy earth or needs a good service or corroded wires to injectors, but its all about trial and error, have you checked pipes under inlet manifold?

 

[sportstractor]

Not sure what the code is but id say if your 100% its not a split pipe then its likely to be the fuel pump dying, i mean it could be anything like a dodgy earth or needs a good service or corroded wires to injectors, but its all about trial and error, have you checked pipes under inlet manifold?

Unlikely to be any of these as the fault is a pressure drop between turn and throttle body. And this code wouldn't display for other faults.

I'd personally take the car in and get it smoke tested, to be 100% sure there are no boost leaks... I presume you have checked all vac lines that go to brake servo and DV, and also that your DV is holding properly. After that I'm not sure what to suggest, I would also like to know what else could this fault code apart from a leak. As I scanned mine a today and it displayed this code, which is strange as I thought I had corrected the issue.

 

[tony696]

My mate had this fault on is Leon after we fitted a gt28rs we reset the throttle body and everything perfect try that mate

 

[Craig1.8t]

I have 25 different things to try cure the cars problem - smoke test being one of em. No leaks at all not even a tiny one unless there's an internal leak somewhere?

Just point point out that one time it ran perfect for 4 days, I jet washed engine and went back to running poor. I've cleaned earths under battery and earth going to gearbox bolt.

 

[Craig1.8t]

For the past 2 days it's been pretty bad, just going to mention that the EPC light has come on 2ce since owning car (had fault with car since owned) EPC is throttle body, right? Hmm it's a strange fault.

 

[sportstractor]

Epc light comes on with a variety of faults mate... Need to get in scanned

 

[Craig1.8t]

Mate not sure if you've been reading.. I have vag com, all measured values appear to be fine and the only fault is 17705 pressure drop between turbo and throttle body. I have tried about 25 things to try get to the root of the problem and still no joy. So I came on here for other opinions. I will post up what I have done tomorrow.

Other than split boost and vacuum pipes what can cause this problem?

 

[sportstractor]

Ah sorry thought the eml was another fault.

You have probably seen this:
http://wiki.ross-tech.com/wiki/index.php/17705/P1297/004759

You can test n249 by bypassing it and seeing if it corrects the fault

 

[Craig1.8t]

Hi mate, been on Ross wiki and done those things, also done n249 by pass before.

I've got a feeling this code is leading me up the garden path and has nothing to do with the way it's running it's really getting on my nerves lol.. I'll post up tomorrow what I've tried

 

[sportstractor]

Have you logged command vs actual boost pressure to see what you are getting?

Not sure if this fault could point to a mis behaving turbo actuator.

 

[Craig1.8t]

I think I've got another actuator come to think of it so that would be handy.. I had vag com on the other day on boost and they seem to be matching, only time it doesn't match is when it wants full boost it's not getting it because it has to build pressure up (does that make sense lol?)

Edit: iPhone auto correct spelling not so clever.