Surging feeling, not boosting properly

[loafofbrett]

Hi all

Having some issues with the car at the moment. The boost is a bit erratic and it simply isn't as quick any more

So far I've replaced the DV and N75 with not much difference. All pipes seem ok with no apparent leaks. I do occasionally get an lambda sensor error that I can clear and it'll go for a bit. Something about intermittent signal on B1S1 iirc.

The car is an A3 Quattro with K03s plus a remap.

I did a little 3rd gear run before with vagcom logging a few things. Think it looks like a knackered MAF? But would a faulty MAF cause the surging, or even a dodgy lambda sensor?

Thanks for any help

 

[<tuffty/>]

What year is the car?

Airflow looks low tbh... try unplugging the maf and have a quick drive... if the car feels better for it chances are the MAF is in need of replacing...

<tuffty/>

 

[loafofbrett]

Cheers for replying mate

I'll try that. Could a faulty lambda sensor cause problems like this?

Oh, the car is 2000 too.

 

[<tuffty/>]

If it can't read values from the Lambda then it will more than likely go into limp mode... is yours a facelift A3? Does it have a wideband sensor? if its not a wideband ECU then it won't be that causing probs under load as it doesn't control fuelling then...

Need to log a few different blocks to see whats going on if yours is wideband... should be able to tell if the lambda is playing up... unplugging the MAF should give you an idea too

<tuffty/>

 

[loafofbrett]

Ok, tried without the MAF plugged in and it still did it, like the turbo is choking on something lol I suppose that rules that out then?

I also did the logging on block 32 at idle which might've maybe identified a leak, but after idling for ages it just stayed at 0%.

Tuffty, it's pre-facelift, i.e. older headlights to yours. AJQ iirc.

Not sure what to try now If anyone can suggest what I could log to maybe identify the problem then please do.

 

[loafofbrett]

Does anyone know if a dodgy lambda can cause similar problems? Thanks.

 

[audi_a3_turbo]

When I unplugged my MAF my car felt flat as anything! like it didnt have a turbo. Is this what I should have expected?

 

[s3dave]

That would suggest your maf may be ok....

 

[audi_a3_turbo]

maybe okay?? well as long as I dont need to spend anymore money on my car lol