The MAF (or Mass Airflow sensor) does the following, and I am quoting from Wikipedia here:
'A
mass airflow sensor is used to determine the
mass of
air entering an electronically fuel-injected engine. The air mass information is necessary for the
engine control unit (ECU) to calculate and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air
density varies with the ambient
temperature and
altitude, and this is an ideal application for a mass sensor.'
Again I am plagiarising from another site here (
www.samarins.com):
'Problems with Mass Air Flow sensors are common. Bad or contaminated Mass Air Flow sensor can possibly cause a wide range of various vehicle driveability problems such as stalling, especially when the engine is cold, misfiring, poor acceleration, etc.'
I have experienced an inoperative MAF myself in my JTD130 which, whilst it was still plugged in, resulted in a very limited power band with no real power unless the engine was running between 2200 and 3000 rpm. Obviously this resulted in some awful acceleration and made for a very unpleasant drive.
Unplugging the MAF resulted in a lot more power and acceleration but I was warned by my local FIAT dealer that the ECU will object eventually if I continued to run unplugged.
After installing a new MAF, my car was even better. Acceleration was even faster than it was when unplugged in all gears and the car was generall more driveable. Fuel economy was better too.
Finally, it might be worth bearing in mind that the MAF is part of the vehicle's emissions control system and may make the difference between a pass and a fail at MoT time. My advice is to get it changed. Look on Ebay if you don't fancy paying dealer prices.
Regards
G_S
!!!
