running problem,need help from the ones in the know!

[AudiS3-Turbo]

had this fault for a while now,basicly if your in a high gear say third,plate your foot on the throttle it will shoot off and you will see around 20psi(revo mapped) and then very quickly drop down to 10psi and remain like that untill you slow down...

It will hold around 18psi of boost if you nail it hard from the 1st gear onwards,its this high gear loosing boost is doing my head in.

So far its had new Maf and N75 valve,the 249 is deleted and my forge is direct to manifold and has a yellow spring so should hold the boost.

The wastegate opens around 5-7psi and i can not find any leaks as it would not hold boost when you nail it from firts.

No fault codes etc...

throw some ides my way please

 

[AudiS3-Turbo]

did i quick log,can someone have a look especially at my lambda values as they are 0 when this happens,is this normal? possible duff lambda ?

EDIT row C is lambda bold is maf.

 

[Matt82]

lambda goes to open loop so is disregarded at that load and those revs, component protection etc.

maf seems very low. my arz (ko3 1.8t) does 156g/s

are you free from boost leaks?

 

[AudiS3-Turbo]

thats good news about the lambda,im going to get better logs tomorrow after reading post on here.

Im sure its not a boost leak as it will spike above 20psi and settle around 18psi when you nail it from 1st onwards,its just boosting it from a high gear that the boost drops off,not gradual it disappears very quickly after 3.5k...i know the k04 puffs out but its not gradual as revs increase.

thanks for your reply bud!