s3 boost problem

[wedgys3]

Hi all new to the forum and to these cars bit different to a starlet turbo well I bought a 2000 s3 amk engine when I 1st got it it was boosting to 21-22psi were as now it's only boosting to 15psi no more got my friend to scan for codes and got these

(p1287 control valve boost pressure n249 open circuit) I think this has been deleted all ready I don't know

p0327 (knock sensor 1 (g61) signal low and another about lamber sensor I pulled the vac pipe off wastegate and it boosted 22psi then only 5psi after that that's how I ended up getting me friend with computer to clear codes boosted back to 15psi now

Any info would appreciate very much as said I no nothing about these and when I read up on things it's n valve this n valve that haha help cheers

 

[Erikn89nl]

Wow, please use paragraphs to keep your posts readable...

Has the car been remapped?

 

[NIGE28]

Smoke test for boost leaks, had the same problem and found a small hole in the metal charge pipe could also be the any of the vac lines under the inlet manifold

 

[<tuffty/>]

(p1287 control valve boost pressure n249 open circuit) I think this has been deleted all ready I don't know

Means the N249 is unplugged or there is a wiring issue... this needs to be plugged in regardless of if you have an N249 delete so that the ECU will perform adaptions

p0327 (knock sensor 1 (g61) signal low

http://wiki.ross-tech.com/wiki/index.php/16711/P0327
Seen this a few times and is typically fixed by rewiring the knock sensor back to the ECU... have done it on my own car and a couple of others before

and another about lamber sensor

The actual code would help...

22psi is the higher end of what these get mapped to... I assume you have a FMIC, 3" downpipe and some for of induction to support this high boost? if not the ecu won't like it and pull back...

This is also assuming its actually mapped and the 22psi is not just down to yet another fault

You will find these cars very different to a starlet... the ecu is far more intelligent and reliant on a multitude of sensors... it will pull back at the slightest sign of a problem to protect the engine...

<tuffty/>

 

[NIGE28]

Yes they are more intelligent then a starlet ( not sure why the starlet got mentioned) but pretty much any turbo car that has a loss of boost etc doesn't hurt to smoke test ? and check the ever problematic vac lines, simple checks which you can then write off

 

[<tuffty/>]

Yes they are more intelligent then a starlet ( not sure why the starlet got mentioned)

Because of this...

Hi all new to the forum and to these cars bit different to a starlet turbo

Smoke test is a must on a 1.8t regardless

<tuffty/>

 

[wedgys3]

Hi thanks for your replys and sorry for me paragraphs I did some sort of smoke test on intake side then weather turned **** I got told by last owner it's been mapped to 270 still on standard intercoolers 3" tip 3"de-cat straight through exhaust to a back box aftermarket air filter that's it the n249 valve looks like it's been taken out and plug is hanging there top right hand side of engine near cam chain I think when I looked at it yesterday I unplugged vac pipe to actuator test drove it got 22psi then dropped off to 5psi obviously that's ecu saying there's a problem going to try a smoke test as long it does not rain

(02 sensor bank1 sensor2 intermittent resistance too high p1114) I plugged car about 2 weeks ago and if I remember correctly I only got 1 code something about boost pressure too high I no it means nothing now as that code had cleared

 

[<tuffty/>]

Hi all thanks for your replys 1st thing I done was a smoke test only used a vape pen like but seen no leaks on vac pipes I got told by last owner it's been mapped to 270 still on standard intercooler 3inch tip k,n filter 3 inch down pipe straight through to a back box only reason I mentioned a starlet as they are totally different compared to these not as technical old school as I would say the car was fine for about 2 weeks then just went like this
(lamba sensor code is p1114 02 sensor bank1 sensor2 intermittent resistance too high) and if iam correct the n249 valve has been disconnected and plug is just left hanging forgot to say aswell yesterday I unplugged vac pipes which goes to wastegate and it boosted to 22psi then dropped to 5psi ****** cars sorry if my grammar is poor cheers lads for ya help

...and still no sentences... can you please at least make the posts readable... Ta

Anyhoo... std intercoolers won't appreciate 22psi for sure... 270hp would be a little optimistic but subject to dyno lottery so who knows... certainly wouldn't be 270hp on the second run, poor old engine would be too hot...

An N249 valve needs to be plugged in... the ECU needs to at least be able to see it for it to be happy

Lambda issue requires a replacement sensor I believe... I am assuming you have a de-cat and that the relevant codes will have been coded out but its also possible they have removed it all together and only caught some of the codes... you would be advised to source a second hand one cheaply and plug it in... this will keep the ECU happy for emissions readiness and will allow fuel adaptions to work

Not sure what pipe you unplugged but 22psi doesn't seem a lot for uncontrolled boost on a K04... also it dropping to 5psi suggests the ECU still has control over the boost as you have effectively gone into limp mode... (actuator pressure)... the actuator would still need to see boost for that to happen... although the ECU can drop load/boost from cutting the throttle but you know when that happens as it like hitting a wall...

You need a proper smoke test... vaping into the charge air system won't really do anything useful

Looks like you have a few things to put right first... and you should ideally be using VCDS to do logging and checking for fault codes as generic readers don't capture every fault VAG cars produce

<tuffty/>

 

[<tuffty/>]

I only got 1 code something about boost pressure too high I no it means nothing now as that code had cleared

I doubt it means nothing... depends on the context... ME7 ecu's use over boost protection... this code will be the result of a positive deviation... its entirely plausible that you car shouldn't be doing 22psi in the first place and the over boost protection has been kicking in...

<tuffty/>

 

[wedgys3]

HI mate cheers for your reply how would you tell if it has been mapped or not would I need to take it somewhere and get mapped myself

 

[<tuffty/>]

HI mate cheers for your reply how would you tell if it has been mapped or not would I need to take it somewhere and get mapped myself

by logging boost request in VCDS... non mapped S3's produce around 12psi... this varies depending on outside temps and several other factors that the ECU sees...

There is no 'boost' data as such in the map... the ECU calculates how much boost it needs to achieve the 'load' requested by the driver (you pushing the accelerator pedal)... in warmer weather the ECU may request more boost as the air is less dense to achieve the load request... in colder weather the boost would be less as the colder air is more dense...

3" DP and TIP will generally up power a tad as the don't strangle the engine at higher RPM like the stock stuff does

<tuffty/>

 

[superkarl]