can any one explain the..

difference/explanation off open and closed loop fueling, people are talking about it , and i think i have the idea but would be good to have a proper explanation. Thanks G.

This is my understanding - somebody please correct me if i'm wrong:
With closed loop the engine gets a complete set of readings to work off - so it has MAF sensor telling it how much air is going into the engine, and then the lambada sensor telling it how close to correct it has the mixture from the exhaust gases.

On a standard coupe, as the revs go up, and the engine load increaes you reach a point where the standard narrow band lambada is not acuarate, or able to respond quickly enough.

At this point the the engine is just runing of the MAF, and air temp sensors -it has some pre set fueling maps for this, and works the fueling out this way - this is open loop.

thanks Paddy, that makes sense , so the loop is nothing to do with the fuel physically, but the devices that control it. kewl G.