Fixing all your keys
AO Silver Member
Join Date: Mar 2001
Location: United Kingdom
County: Tyne and Wear
Re: 156 1.8 ts high idling poor performance
It will take some time to get back to normal after a butterfly clean, possibly a few weeks if you don`t drive a lot.
If its taking a while the you can reset the ecu to get it back to factory defaults by disconnecting the battery for 15 - 20 minutes and although it will be a little rough for a while it will soon 're-learn' the car. At least this way you can see if there is another problem somewhere else.
ECU remap is when an after-market map is put into your car. The map controls the basic settings that allow the ecu to work out how much fuel to deliver based on throttle position, rpm, temperature (air and water) and a few other things. Fine tuning of the map setting at any given moment is moinitored through various settings but the map is the main default setting. It will also control rev limits.
The map is designed by Alfa to give a safe and average performance in a all of the wide variety of possible scenarios for driving around the world, but an after-market map is usually refined to push the limits of what can be acheived by giving more accurate mixtures and higher rev limits. Basically its a form of tuning the ecu to give the best performance from your engine by cutting down on the safty margins that alfa have built in, but this needent worry you as the margins are quite conservative to start with and most remaps don`t cut them to a point where they will cause the engine any harm.