epc on car stalls a3 1.8 petrol

[b2online]

Hi Guys
I have an Audi a3 1.8. bought it from a dealer and now the dealer is closed down hence no warranty...

I need help from the Guru and reading the posts I have seen your work please help.


Problems with the car.

• Dosent start properly unless I press the acceletor for about one second immidiatly after turning the ignition. If I dont rev to about 3000 rpm immidiatly then the EPC light comes on. and the car is in limp mode.

• EPC and ESP light comes on every now and then and at this time the car stalls and also the battery light comes on. This normally happesn when waiting a long time in traffic. or slowing down at signals or turnings.(really dangerous)
• The rev needle is very eratic at times. highly noticable when the car is idle. normally the needle is suppose to nbe at 750 RPM when idle but sometimes goes up ti 1100RPM and sometimes dips lover then 500 RPM specially when you rev and leave the acceletor. At time it goes all theway down to 0RPM and the car stalls.
• If the car stalls too many times then the endine management light comes on.
• To give you an idea it stalled today about 5 times ina distance of 1 mile and hence had to take the train.

Any ideas as to what might be faulty from the above symptoms.
Thanks alot for reading and helping out.

[dave212121]

My suggestion would be to check the MAF sensor - the mass air flow sensor tells the engine how much air is entering the engine and the computer mixes the flow for the best performance.
If it is sending bad signals the engine will not know what is going on and could explain some of your problems...

Your MAF is basically a wire that is kept at a set temp (usually 200c) and by calculating how much energy is needed to keep it there the computer figures out the volumn of air passing. fine dust and other particles fuse to the wire where after a few years the readings are affected as the wire is essentually insulated.

cheapest thing to do is take it off and spray the MAF wire with carb cleaner which may work but probally will have to fork out £80 - 90 on a new genuine one.

see what everyone else thinks though...

dave

[b2online]

Hi Dev

thanks for this reply. I have cleaned the MAF with a vacume cleaner fairly because i didnt nave the right tools to remoce the MAF from the intake pipe

I will remove it with the right tools and clean it with carb cleaner as mentioned by yourself.

I have also read the posts of other users and one thread was to clean the throttle body as well. Do you think that is worth doing.

I will try the above and post what happened.

thanks again

[dave212121]

Hi,
never actually cleaned a throtle body yet so cant really say too much about that area - i'm also not a mechanic, just enjoy tinkering with my S3..

The reason I know a thing or two about MAFs is that i changed mine a few months ago - firstly with a poor quality aftermarket one (which caused jerking , stalling and all manor of unusual behaviour) which i then returned and got a proper one from Audi.

The carb cleaner appartantly works for some (depends on how visible both wires are - sometimes one sits behind the other, others it sits up a seperate tunnel) but usually its only delaying the enevitable replacement.

a genuine one should have a white audi sticker on it somewhere- if not (and isnt BOSche (mine)) that may be your problem. The cheap one for my car was £35 - the genuine one was £80ish. Euro car parts can do the proper one for a bit cheaper but in my case it was only £2 cheaper...

I have read other threads where it says an auto electrician could do a resistance test to see if the MAf is the problem..

hope this helps a bit

dave

ps - dont destroy your orginal MAF - you have to trade it in when you get your new one and thats even the case with AUDI