what controls the boost on a agu?

[dan2252]

hello having yet more troubles with lack of boost and its just allover the place basically all im wanting to know is how does the car increase boost and then know when to drop it off? its a agu running a k03s standard atuator. car did run 22psi now its holding more like 8..

[Granta Gti]

N75 controls the actuator so I think that could be playing up

[jamie1989]

Noo it could loads of things mate.
Weak actuator?
Boost leak?
Is it peaking at 22psi still?
If not maf could be goosed?
Are you running standard dv or 007p?

Dont just assume its the N75 buddy in my expeirence the N75's are pretty good iv never had one fail on me. Its nearly always hardware issues.

[dan2252]

Thanks for replays guys no its not peaking at 22psi still peaks at 15 if your lucky then drops off to 8 psi followed all the boost pipe work and I can't see a leak, if you floor it off the line you get a what I can only describe as a high pitch chatter noise, but ive had all the pipes off and there are no leaks, actuator is fairly stiff to move, fitted a new genuine n75 6 month Ago only fault in system is for a coolant temp sensor

[Wazzzer]

Sort the coolant sensor first mate as the fuelling could well be out. I would look at your DV next

[dan2252]

Got a apr recirc valve on its about 18 month old, and il get a temp sensor today then could a faulty lambda cause low boost?

[Wazzzer]

The noise you are describing sounds like the N75 going nuts to me...

[dan2252]

I don't think it is mate fitted a genuine one 6 months ago but il swap it later with a spare one I have see if it make a difference any ideas are welcome sick of it been so flat

[JimBR]

My friends S3 had loads of turbo chatter when his standard DV failed. Swapped it for a 007p and it was fine. Maybe an idea?

[jamie1989]

It sounds like you have a boost guage plumbed in.

Have you checked everythings still connected properly with no leaks or any tubes collapsed (strange I know but Iv come across people using window washer tube which are plastic and they collapse easily, makesure you use silicone either 3 or 4mm)

Is it plumbed into the fbr only? or have you plumbed it in the DV (Plumbed into DV is wrong and causes alot of chatter also)

Any other vaccum leaks? AGU have the horrid 90' degree rubber pipe on the on the rocker cover this splits, so do the rest of the PCV system including the plastic 90' tube coming from the oil filter housing check everything around this area.

Without physically checking the car over it could be soo many different things so all we can do is throw potential causes at you