The Lambda (Oxygen) Sensor saves the day Ignoring all the subtleties, a good combustion will produce an Oxygen level at the exhaust that is equal to that of the surrounding air - Lambda sensors measure the difference in Oxygen concentrations between the outside air and that in the exhaust. So - engine manufacturers added a way of checking the fuel/air mixture by using a Lambda (Oxygen) sensor. But, it is pretty obvious that there are going to be errors, and early engines had an adjustment for the air measuring device (which was an AIRFLOW METER rather than a MAF) so that you could compensate for wear, air leaks, blocked injectors and a myriad of other possibilities. The target is to get the fuel/air ratio correct because this provides efficient combustion and clean exhaust gasses. So, above is the very basic plan - measure the air input and decide on how long to open the injector - this happens every camshaft revolution. All we are interested in is the basic fuel/air mixture which is provided by measuring air MASS (with a MAF sensor) - the ECU (engine computer) then computes how long to open the injector for: And to do that we are going to look at a single cylinder of our engines and ignore all the other sensors. To get us going we are going to have to understand adaptations first! ADAPTATIONS Looking at the stored adaptation values gives us a good insight into the condition of the engine and the source of the problems you may be having - so we are going to have to understand them first. There is loads of advice on the Forums that say ‘you need diagnostics’ - but what do you actually do with diagnostics - and what do all those values mean? This document is for those that have engine running problems and want to fix them with the help of diagnostics - in this case we are using INPA. Timm's BMW Engines - Diagnostics and Adaptations What are they all about and how to fix engine running problems This is a big subject - engine running problems and adaptations - especially ‘adaptations at limits’ which light up the engine warning lamp.
0 kommentar(er)
