A3 Hesitating

[Keefo]

My mate has an A3 that when he puts his foor down (even when going slowley, but more noticable when tryin to boot it)
when he tries to accelerate, it gives its normal power, then takes it away, but still accelerating just ALOT slower, then gives full power again.. and again and again...

its hard to explain but its just boggeling my mind as to whats going it!

Its just like its giving up on givng its full power, then trying again.

Anyone else had anything like this? or know what the problem could be?

he has tried error reading and just basicaly says "missfiring" and thats about it... no reason to why its missfiring...

i belive Its recently had loads of turbo pipes replaced to try and fix the problem but it has not made much differance at all.

Also tried new Spark plugs and some other minor things like some cencors..

 

[wibble111]

MAF problem maybe

 

[Keefo]

errm, im new to all this, whats the MAF?? haha

:edit:

ahhh its a sensor! where abouts is this sensor ???

 

[HTC]

Mass Air Flow sensor. The tube that attaches to the airbox and turbo inlet pipe. On some engines it can cause these symptoms when faulty. You can try unplugging the electrical connector and driving the car. If the misfire dissapears then you should have found the problem.

 

[wibble111]

Thats the one ^^

Beat me to it.

 

[Keefo]

ahhh cool, i will give it a go next time i see him!

hopefully this will b causing the problem, if not then crap!! back to the search lmao

 

[Keefo]

Oh yeah, just incase this is a clue to the problem....

It has a dump valve fitted, and sometimes it fills and is loud, and sometimes (most of the time) its very quiet and u can bearly hear it at all....

 

[HTC]

If the car isn't making boost all the time then there will be less pressure to dump.

 

[Keefo]

ahhhh ok, so it still could be the MAF!!

ok cheers

fingers crossed haha

 

[jbw]

Oh yeah, just incase this is a clue to the problem....

It has a dump valve fitted, and sometimes it fills and is loud, and sometimes (most of the time) its very quiet and u can bearly hear it at all....

From conversations I've had with other folks on this forum I'm under the impression that audi (vag) engines don't really like dump valves much.

 

[Keefo]

hmmmm ookay

Will see if thats causing the problem too!
Should be able to test it this weekend hopefully

 

[nickrex]

Oh yeah, just incase this is a clue to the problem....

It has a dump valve fitted, and sometimes it fills and is loud, and sometimes (most of the time) its very quiet and u can bearly hear it at all....

VAG cars shouldn't have a dump valve fitted as the ecu is expecting air back in the system. This is why there is a diverter valve instead. Does't sound like your problem though, as mentioned before, unplug the MAF and go from there. Like alot of people on here, I've had my share of MAF problems on my audi and my old golf anniversary. Very common fault.

 

[Keefo]

Is there any way to make them Dump valve friendly? haha

what could happen if you keep one on? what do they do to deam them not nice on VAG cars?

 

[Keefo]

Also, the car sometimes will not start first time... and will need jumping before it will start, but according to battery checks he has had done, the battery is fine.

Anyone hear of anything like this??