A3 MAF sensor and slight bouncing idle !!

[bree9482]

Hi guys ew to the forum and audi's for that matter also !!

I have owned my 2002 A3 1.8T for a week now. All in all its a fantastic lttle car. Its had water pump, timing belt and rear bushes done 1k ago. Almost full service history. Imaculate iinterior and generaly in great condition.

Anyways im having 2 issues, First one is idle speed. The car once auto choke has disengaged will idle 800 but pulse ever so sliightly to prob 850-900. Second issue was aroud 3500 revs there was a slight flat spot, but car would just pick up after it gt passed it.

Whatl have done so far is injector cleaner into half tank of optimax, taken off MAF sensor and cleaned with electrical contact cleaner(did not remove from housing as ould not find torx bit).

Took the car out for a spin and it seems to be pulling better and from what i can tell flat spot seems to be gone...

However the idle remains the same. I have called audi and they have advised that the car has still to have the coil packs replaced, so that is getting done on the 17th May.


Is there anything else l can do ?? I was going to just take the MAF plug out and see how the iidle is, but l beleive that would turn on the engine management light ??

Any help is much appreciated

Brendan

 

[basil brush]

Clean the throttle body , sorts most idle issues
baz

 

[bree9482]

Hey Baz thanks for replying !! Not sure how to do that. Too youtube lol !!

Cheers

 

[basil brush]

Can if carb cleaner , remove multi plug , undo 4 Allen head bolts (5mm) and get busy with the carb cleaner and a tooth brush DO NOT open the throttle butterfly by hand as it could wreck the stepper motor , have a new gasket hat hand as yours may tear on removal ( only a couple of quid from the stealers ) and of you haven't got vcds to align the throttle after re fitting it be prepared for a few miles of erratic idle which WILL sort it's self out
baz

 

[bree9482]

Hi BAZ so dont open the gates ??? What about the gunk inside ?? Will l really need a new gasket, l want t go do this now but audi shut till monday??

Cheers for the help mate !!

 

[basil brush]

No DO NOT open the gold coloured disc inside !
your aiming to wash all the gunk out with the carb cleaner and brush .
i bought a gasket and turned out not to need it but it does happen !
Baz

 

[bree9482]

Hi baz ok just cleaned the throttle body. It was full of grease and gunk on the inside !! Totally clean !! Built back up and let car idle for 20 mins. It was all over the place, but settled at a normal idle. Took for a spin was driving really smooth !! I think the flat spot is gone... And the idle is much better but still moving a little. I only done like 2 miles. I think u said it would take a few miles to settle ??

But that's about all I can do, the car runs great just that idle !! But the coil packs are getting done soon, that should only help aswel !!

cheers for your help !!

 

[basil brush]

Your welcome
Glad to be if assistance
baz

 

[bree9482]

Hi Baz, the car is still running a little better however. I was out the other night and felt like opening her up a little.... Well with WOT in 3rd gear around 3500-4000 revs the car stumbled a little and then the traction controll light came on. No other light just the yellow triangle. It would not switch off by pressing esp button. It goes off and stays off after cycling ignition. Under normal driving it does not come on, but again today to see if this was still the case l gave it some wellie and hey presto traction control light !!!

too add l have disconeted the MAF and astarted the engine, i never drove it just let it idle for a couple of mins and no engine warning light !! i have re conected it now but was only trying to see if the cars idle improved. I have also checked the pressure control valve by removing the oil fller cap and no sucking !!

Im really concerned about the MAF sensor and why the engine management light never came on after disconnecting the sennsor ??

Cheers Baz any help would be awesome !!!

Brendan

 

[basil brush]

A maf fault will bring the ESP light on
guess your running issues were gunked throttle body and a maf problem !
Your half way now you've done your TB , have you cleaned your maf ?
If not got some security bits from screwfix and take out the element from the housing and use some more carb cleaner but DO NOT touch the element it's self
baz

 

[bree9482]

Hi Baz, yeah done the MAF first but never took it out of the housing due to the torx bits just spayed throught the plastic grills. Its still not idling prop and now the traction control light ?? why would that come on ??

 

[basil brush]

MAF fault !
Baz

 

[bree9482]

So the MAF would bring on the TCL under heavy acceleration ???

Do you recomend me just buying a new one or whats the best thing to do ??

And thanks again mate !!!

 

[basil brush]

The ESP gets a torque calculation in relation to the revs from the MAF so any faults in the MAF result in the ESP going haywire , and as your reporting idle issues I would say yes go for a "genuine" MAF ( not much dearer but s*it loads better ) .
BUT I have been wrong about lots of things before ( marriage being a good idea being the biggest faux pas )
baz

 

[bree9482]

Hi Baz, hahaha marriage lol. Ok so im just back in the house and now the traction control light is on permenatly. I gave it some and it felt like the car was slowing me down on its own, like a huge pull back then a hesitation the the light cam on again and now it wont go off. No other light are on at all. Car still feels like its got power and pull.

Do you think i should disconect maf plug and drive ???
And even if l get a new MAF will it need to be hooked up to clear the code on TC ??

God ive had this car a week and im stressing like mad lol, tbh l think its something simple like the MAF as everything is pointing to it !!

Brendan

 

[basil brush]

don't stress man , keep a level head and work methodicly ( easy to say i know but ive been there with many cars with many faults )
fitting a new MAF will require a code being turned off yes .
buy one of these U281 VW Audi Skoda Seat VAG CAN BUS Fault Code Reader Scanner diagnostic tool UK | eBay i did and it's paid for it's self 10 times over
expect to be clearing code "17535"
i personaly would buy the cheap code reader , hook it up and see what comes up , then go from there .
order it now and you should have it by wednesday
baz