Accelerate jerky, idle rev up and down but not MAF issue

flippy

Registered User
Joined
Jan 23, 2009
Messages
20
Reaction score
0
Points
1
Location
NULL
Having a pain problem after change timing-belt, water pump, air-filter on my S3 8L AMK. the symptom pretty weird, idle rpm goes between 1k or drop to 300 rpm (almost dead). feel very jerky when accelerate to 3k , can't accelerate when reaching 4-5k. When we try to un-plug the MAF sensor and car can accelerate smooth as usual except 2 light on dash come up (engine & ESP) My Garage think MAF sensor might dead which i see most people had the same problem by reading the forum. Have try 2 different brand new MAF sensor change but problem still exist, then try change coil pack but nothing help. try Vag-com to see any DTC, see nothing come up special except below

1 Fault Found:
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - - - Intermittent
Readiness: 0010 0101

This DTC show when car in MAF sensor un-plug condition which we think is normal. It show no error when we plug MAF sensor back.

The car was Revo stage 1 tuned in previous owner before my hand and pretty much are standard without other modify (engine part) . Any suggestion or advise are deeply appreciated and welcome, hope can be a hints for us to trace what problem it is now. Currently i force to un-plug the MAF sensor when using the car but scaring it can't use in long run as ECU can't reading any air-flow figure that might harmful the engine if keeping for long without fixing.
 
have you actually logged the maf readings? that's the only real way to tell if a maf is gone!
 
sorry didn't read that properly! first thing i would do is log the car, does it break up at all when under heavy load?
 
My garage did the log but i can't understand its mean, but funny is even we change a new MAF but problem still exist, it happen even the car in idle that we can tell something wrong, now it force me to un-plug the sensor and drive but worrying its might harmful for the car if leave it like that.
 
have you done a throttle body alighnment?
 
May you suggest idea how to do ? i believe it might involve VAG-COM. Correct me if i am wrong, thanks.
 
it can be done via vagcom through adaptation or you can dissconnect the battery, re-connect turn the ignition on (leave with the ignition on for 30 seconds or so) then start
 
Thanks for quick prompt Carl, I search about TBA and someone said below

open driver door, turn key on, wait 30sec (with hood open or keen ear, you hear high-pitch throttle motor aligning), close door and start engine.

Is this correct way to do also apply to my 8L S3 ? looking forward to hear you soon.
 
Just follow the Rosstech guide and got the TBA done via Vagcom, but problem still same. This problem is so weird which i also thought your advise must work but kinda feel sad we all guess is wrong.
 
My friend, today november/2013 I have the exactly same problem with my S3 8L.

I changed the MAF for a new one 3 times, and still doing the same problem.

Did you get a solution? Did you find out the problem?

Thank you very much
 
check your PCV pipes. Mine has been doing this recently so i replaced the MAF and didnt cure it so checked for leaks and found a huge tear in one of my PCV pipes which is what it turned out to be. Tear
 
seems a plethora of these type posts on forums, Facebook currently.
maybe the cold weathers killed off the perished pipes

Vac leaks and boost leaks from pipes assiociated with the pcv breather system and inlet manifold are VERY common.
look for pipes which have oily residue on their outside.. and there will likely be a leak Close By!

Smoke test will reveal if you have a local garage who can provide the service.