This ones got me stumped :-(

[A3 T]

Well guys another day another problem

Today i pulled on an A road and as soon as i tried to accelerate to merge with the traffic, the cars boost shot up and the car felt like accelerated very lumpy and then just wouldn't accelerate any more.

I ended up having to go into a too higher gear and then let the car slowly gain speed.

On my way back i took more notice of what exactly was happening and it seems like as soon as the revs get to about 2k the boost gauge goes mad and either shoots up to 10 psi or it fluctuates to about 10 psi and the revs go up to about 3k, at this point the car sort of kicks back as though I'm maxing out the cars speed.

I tried unplugging the MAF (although its a new one) and it did feel a little bit better but the problem was still there.

I've also logged the MAF reading in vagcom and raised the revs to 3k and it showed 10/gs so no problems there.

And there's no faults showing up in vagcom.

My thoughts are..

N75

Coil packs (as the lumpy feeing felt a bit like i unplugged a HT lead).

Turbo (although im still getting good boost, its just comming in too fast...lol).

MAF (maybe the fault is a high revs).


What do you guys think?

 

[IPG]

sounds like overboots then hitting limp

on turning off the car and restarting do you have all your power back?

i would check for leaks on any of the hoses to/from n75/DV/boost hoses

 

[A3 T]

sounds like overboots then hitting limp

on turning off the car and restarting do you have all your power back?

i would check for leaks on any of the hoses to/from n75/DV/boost hoses

Thanks for the reply

Yes it does seem a lot like over boost but its only hitting 10psi and its getting to 10psi at 2k revs.

Also i've suffered with overboost in the passed (when i tried a race n75 valve) and while it did feel the same when it hits 10psi this i a LOT more lumpy (that's what was making me think it was a coil pack).

Turning the car off and on makes no difference as just coming off the accelerator brings it back to how it was before.


I have checked all the hoses and i cant see anything split and to be honest most of them have now been changed to silicone ones.

 

[IPG]

lumpy idle may also be leaking vacuum lines. check those too

keep checking for boost leaks - especially now you have changed all boost hoses to silicone - re tighten them all properly

 

[Broken Byzan]

clutch slipping?

 

[ayfreetee]

Sounds like n75, I had a wavering boost on my old A3, it turned out to be the n75 breaking down, can you borrow a known good one to see if it cures your problem?

 

[A3 T]

Thanks again for all the replies guys

Today I put my old faulty MAF back on just to try it and it's seems to have fixed the problem (it's now just drinking fuel...lol).

So it seems like my new genuine MAF has failed after just a few months.

 

[ayfreetee]

Hope you kept the receipt

 

[westcoast a3]

Have you scanned with vagcom??? Do you have any codes ??? Are you sure it's fixed it with it, using loads of fuel ?? Have you tried to drive the car with your new maf and the n75 unplugged to see if it drives better ???? But with only 5psi boost, if not I would try that first to eliminate that


Sent from my iPhone using Tapatalk

 

[A3 T]

I've now fitted a new MAF and it seems so have fixed it.


I do still have a bit of a problem when the boost maxes out and instead of just hovering there it sort of kicks back and runs bad.

But at least i've solved one of the many problems....lol