As the title implies, this is not a book specific on ECU's. However, it does contain a chapter on ECU's and how they work. The more interesting thing about this book is that it handles all kinds of aspects of an engine. From air intake to exhaust, fuel delivery through carburetors and fuel injecting, to bottom ends, lubrication, cylinder heads and camshafts.

The interesting thing is that the author explains the basic subject, including the theory behind it with formulas. Then he uses examples from his work to explain and put the theory to practice. This gives some very useful guidelines to work from when attempting to make a change to an engine. For example, the book contains some useful formulas on injector flow. Using the formulas it is pretty easy to calculate the required flow and see if a certain injector is going to be big enough for a project.

The book is setup so you can skip to the chapter you want to know more about, and use the information without having to have read the whole book.

Although I haven't put any of the theory into practice, the book looks like a very handy reference when changing or tuning an engine, and will give you a ballpark on what to do and what not to do.