This page is intended to orient the new user to the ECMLink system and, to some extent, ECU tuning concepts in general. If you just received your package and really have no idea where to even start, this is probably the page for you. If you already know how to tune an ECU and already understand basic engine operation, then this page is probably not for you.

It's simply impossible to give a full account of engine operation and ECU tuning concepts in a couple paragraphs. So please don't take the following as a complete summary of everything involved. It's not. This section is intended simply to orient the reader's mindset in the right direction with some high level concepts.

The engine works by igniting a mixture of air and fuel. The ratio of air to fuel is a key ingredient in producing power. Too much air or too much fuel (or too little of either) causes poor running conditions, misfires, etc. The mechanism used to ignite the mixture is a spark from the spark plug. The exact timing of this ignition process relative to piston position is another critical item in producing power. This is call “timing” or “ignition advance”.

The whole process of injecting fuel in the right amount related to the amount of air going into the engine and firing the spark at the exact right moment is all coordinated by the ECU. The ECU needs to know how much air is entering the engine to know how much fuel to inject. It also needs to have some idea of how much cylinder pressure is involved to schedule ignition advance appropriately.

The amount of air going into an engine is a critical piece of information the ECU needs to know very accurately so that it can accurately calculate how much fuel to inject. If the real airflow going into the engine is different from the amount the ECU thinks is going into the engine, the ECU will schedule an inappropriate amount of fuel and the engine's operation will suffer as a result. So accurate airflow metering is really important.