Help with my over boosting please

[BoostHard]

Ive never done a log before, I don't have Excel so I cant save it from there,
Only able to take a snip of the screen,

My car is over boosting,

It went into limp mode whilst doing this log.


1st Log is with N75 plugged in and 2nd is with the N75 unplugged:



N75 plugged in

N75 Unplugged

 

[brad_barker12]

that is weird, your car is underboosting below 3500rpm then when you go above this it overboosts lol. I found out today why mine is overboosting. appears it has a standard map and the mods require a stage 2 remap

 

[BoostHard]

so what has been modded to cause your overboost?

 

[brad_barker12]

its pretty much stage 2 ready. Cobra 3" turbo back exhaust, SFS 3" TIP, Jetex induction kit & Heat shield, N249 bypass, 4 bar FPR, Forge 008

I did some logs and the car is only requesting 1800 mb which is what a standard map requests. mine goes above this everytime.

 

[BoostHard]

So is it looking like mine is related to the turbo/acutuator as it drives the same with the N75 unplugged,
Still overboosts like crazy. I have removed and checked the hose from the actuater and its fine, no splits and conected properly?

 

[BoostHard]

Ok, so I have edited the 1st post to show N75 plugged and unplugged.


Can anyone tell me what they mean please and what I should do next?

 

[brad_barker12]

do you have any fault codes aside from the overboost code?

 

[BoostHard]

Nope, Although today I did have 'mass airflow (g70) signal to high,

guess its dying or something?

 

[brad_barker12]

I woudnt be so sure on your maf dying.

my overboost issue I believed was due to my maf sensor.
basically when I put my foot down at high speed the car would go into limp mode and my ESP light would illuminate which normally indicates maf sensor fault. had the car scanned and it showed MAF signal to high and the overboost code. I assumed the MAF was at fault and the reason the car was overboosting and going into limp. I bought a new MAF from eurocarparts which had no effect. I gave the maf to my mate whos a member on here (285cupramatty) to test on his LCR and it worked fine. I had read various threads saying eurocarpart MAFs are abit dodgy so I bit the bullet and bought a genuine MAF from seat. again this made no difference and still getting the overboost and MAF fault. I then decided to buy VAGCOM. after doing some logs it appears its overboosting due to my mods exceeding the map. the car overboosts therefore taking in more air than the map wants.
the MAF is sending info back to the ECU that more air is coming in than wanted therefore making the car think the MAFs at fault.

I believe that's why your getting exactly the same codes

 

[BoostHard]

hhhmmm! I guess my best option is to make the time and get the car looked at properly.

My car smells really fumy when I 1st start it. Like pure petrol, It clears after a minute.

Its only whilst the car is on the fast choke idle.

 

[brad_barker12]

to rule out maf sensor do some logs
measuring block 002 and 115 I believe.
im still fairly new to all this vag com logging stuff ive had to learn what little I do know fast lol.
bloody 1.8t's! lol

is yours standard?

 

[BoostHard]

its a standard map,
Only mods I have are a Badger V3 Tip, Forge 007p with revised piston, Jr cone and a boost gauge.


It was doing it before i fitted the Tip and the cone

 

[BoostHard]

Rick@Unicorn has just sent me this message:


You either have no pressure feed to the actuator, or the wastegate is stuck open. Or, someone has fitted/adjusted the actuator wrong/fitted wrong actuator.

Apply pressure to the actuator and take note when it starts to move. The N75 may have failed open, so bypass it by joining he line between the actuator and inlet and blocking the third port off. Then check boost again.





Going to give that a try tomorrow.




Bill had already advised to do the bypass but I didn't get round to it, will deffinately give it a go tomorrow

 

[brad_barker12]

mmm I really don't know what to suggest. I would ask bill from badger 5 about this, he helped me and is very knowledgable on these cars

 

[ibizacupra]

the confirmation of this is electrically disconnect the n75 and see what pressure it runs at... Expected would be 6-8psi region...

 

[dazjstuart]

mmm I really don't know what to suggest. I would ask bill from badger 5 about this, he helped me and is very knowledgable on these cars

Hmm this sounds pretty much exactly like mine, your logs are pretty similar. Does yours dump boost when on throttle? Mine boosts like hell then it dumps it (you can hear the DV) then builds boost then dumps it again.

What pressure should the actuator start to move at? How do you free it up if its stuck? How likely could it be for a faulty MAP sensor to be giving wrong boost readings? Sorry for all the questions lol.

 

[BoostHard]

Bill the last log was with the n75 electricly unplugged and it still boosts wildly over 1.5bar. Turbo was Recon unit from midland turbo

 

[ibizacupra]

Bill the last log was with the n75 electricly unplugged and it still boosts wildly over 1.5bar. Turbo was Recon unit from midland turbo

ah.. justr re-read that bit, sorry

Midland turbo.. Sorry but Opps

there's your problem right there..
Boost creep because they have used a Chinese hotside which has too small a hole in the wastegate so it Cannot, no matter what you do bypass enought flow to control boost.
You are stuck with this and turbo will need to come off and the hotside ported to the right size.

You are the 3rd Midland turbos K04 car I have read suffering this.

CN hotsides out there are majorly undersize wastegate ports

 

[ibizacupra]

read here> http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/179289-overboosting-mk2-20v-amk.html
and here> http://www.audi-sport.net/vb/a3-s3-...4-off-ebay-china-have-read-inside-beware.html

 

[dazjstuart]

Sorry to hijack again, just tried mine with the N75 unplugged, it made no difference to the boost. Any ideas what this means?