Well ive gone out and bought myself a tuning book from the pitstop bookshop titled - Engine Management, Advanced Tuning. and so far (1/4 of the way though) is a great purchase.

the author starts right from the beginning, going through AFR's, Lamda, timing etc but also alludes to alot more detail later on in the book.

ill let you know how the rest of the book is - its my 'bus ride' reading....

Steve