1.3-1.5 bar boost - aby - boost leak???

[S2Ian]

That is correct, I noted the boost levels of your car here http://www.s2forum.com/forum/showthread.php?t=10806

It boost higher then drops because of the overboost function of the ecu of the ABY http://s2central.net/motronic_03.html

It will never hold maximum boost for more than 15 seconds.

no way should it be boosting to 1.7 bar. It only has a 2.5 bar MAP sensor in the ECU which means it can only control boost to 1.5 bar max.

im only going on what the boost guage on the top of the steering wheel told me, it was telling me that it was going up to 1.7 bar, id never hold it there for 15 secs i just knew the needle would go round that far. but at the mo it wont even sustain 1.5 bar and there seems to have been a drop in torqe, ive read some threads and cant fatham what it is, will change the oxygen sensor, and the lambda probe, and need to get it plugged into a diag machine to find the fault codes....

im not making stuff up im just trying to be as descriptive as i can with the things i have available in front of me. im a little confused as its just happened after it came back from garage to have springs and bushes fitted, figured they may have knocked a connection so checked them all and i cant find anything, will be coming with it to billing next saturday so maybe someone can look at it there, as i feel like such a noob when it comes to these cars...

kind regards, ian

[S2Ian]

from what has been said, relative pressure seemed to be 1.7 bar about 3 weeks ago, then it went in for springs, and bushes, has had mot and they cleared some fault codes apparently regarding the lambda probe and now i have this quandry.... im trying to be clear with what im saying but appologies if im not as it seems i am lacking in overall knowledge of the way the engines work and the seperate bits that may be contributing to the problems im having..

as for the boost guage, its been working the same ever since i got the car last year, but will try getting hold of another one to rule it out.

thankyou to everyone who is helping.. with my strange problem

[Jamo]

I'm not doubting mate honest.

The ECU cant boost more than 1.5 bar so it's doing more then something is up.

2 things that may be up.

a) The forge diverter may need cleaning. You'll here it recirc because it's got the weak spring in. I used this as it reduces lag.

b) Pressure test I had problems with lose hoses in the system as the clamps over time would work lose

c) O2 sensor going is moody! I replaced it in 2005 with an OEM from Vagparts if it's gone that's bloody bad luck

Ben and myself will have Vagcom at Biling.

[S2Ian]

cool, was just reading about spiking, maybe thats what was happening? how much is a wastegate frequency valve? if its not much i could change it just to be on teh safe side? i am a bit worried as i know its not as torquey, not by a lot, just a bit, maybe ill get someones opinion at billing, can get lambda and o2 sensor from ecp as used to work there and they are same as oe parts.. if not needed ill take them back, would jsut be good to be round people who actually know what they are on about... warey of taking it to stealer and to poeple who claim to be "audi specialists" would rather poeple who own one and mechanic have alook im just cautious lol

[Jamo]

O2 sensor you can change yourself, it's quite easy ( well should be for you I put antiseize compound on it, took a bit of brute force to get the old one out ).

GSF, Bosch, ECP there's a few website listed on here that sell the O2 sensor.

WGFV is easy as well, again there's quite a few threads on here. That was changed in 2004.

Thing i'd look to do is the fuel filter. It was on the to-do list when I had the car.

[LHD_Kid]

can get lambda and o2 sensor from ecp as used to work there and they are same as oe parts.. if not needed ill take them back

Lambda sensor and O2 sensor are different names for the same part....
Good luck with the problem...