Pilsk skrev:

är du säker på att det inte är stöldskyddet som krånglar? Om dom tjorvar så går bilen i bara några sekunder när man vrider i gång den. men när man vridit igång den några gånger på brukar den gå.
Är vanligt på a4 att stöldskyddet krånglar

Pilsk skrev:

lyser det nå lampor eller nå.
startar bilen varje gång du har dragit ur lmm?

Kornz skrev:

Bilen skall ju gå in i ett så kallat limpmode när lmmen är trasig... Då skall bilen gå att starta iaf men den går som en påse nötter. Du borde gå till skroten och fixa en ny lmm och se om de hjälper.

MAF – Mass air flow meter is used to measure the air going into the engine. It is located on the outlet of the airbox, and housed in a cylindrical tube. The ECU reads the MAF signal, and injects fuel in proportion to the airflow. There are a few different ways the MAF can fail. The MAF can get coated with oil, and will not read properly. This is common if it happens right after installing a CAI, or a K&N filter. It can be cleaned out with 99% isopropyl alcohol, or a quality electronics cleaner. Remove the sensor from the housing and clean the sensor element.
MAF sensors also go bad due to too much airflow. On a car with a larger turbo the airflow is so high that the MAF element will get burned out from the excess air flow. It is common to increase the size of the housing to prevent this (other modifications required).
To check for a BAD MAF the best way is with a VAG com. Block 002 show air mass from the sensor. At idle the air flow should be 2-4 grams/second. With a wide open throttle run to redline the reading should show up to 170 g/s on a chipped car. Look for jumpy readings in the MAF, which can indicate a problem. More details here http://www.ross-tech.com/vag-com/cars/fuel-trim.html if you suspect your MAF is bad, one way to test it is to unplug the MAF, often if the MAF is giving false readings and upsets the fueling. If you unplug it, the ECU will ignore the MAF and run off of baseline tables. Be careful, as a boost leak or a vacuum leak can be miss-diagnosed as a bad MAF, because they will throw off the readings on the MAF. (Air sneaks around the MAF).