Basic Fuel Injection Layouts

Basic Fuel Injection Layout.

I like this topic because I like drawing diagrams of how things work.  Now why do I like drawing diagrams? I am also into architecture, and I used to draw lots of building plans.  The reason why I like graphs, diagrams, plans, etc. is because looking at them and drawing them allows you to think outside of the box.  When you look at an engine bay and think about it, you can only think so much. But when you draw up a diagram of what's going on in that engine bay, you can think about it a lot more clearly.

Now, as boring as a diagram of an ECU's inputs and outputs would look like, since it's so "boring", it's because it is simple.  When I am asked questions by Hans on what would happen if this happened, the first image I think of is a diagram.  Especially in electronics,  when you put your multi-meter in a certain place, of course, it will be easier to think about a diagram rather than looking at the actual circuit (especially the ones that Unitec supplied us with, they actually tend to make things seem more sophisticated than they actually were).

Now here we have a diagram of an EFI system with all of its components including the sensors, actuators and ECU. we can clearly see what's going on here.  Yes, we can get more detailed with all of the individual cables that run to and from the ECU etc.  but in this case, we are only thinking about "what goes where".

You might notice that this diagram cannot exactly represent all EFI systems, yes it runs on a dizzy, yes it has a (not very common, at least as far as I know) a L-Jectronic MAF, and yes it is a 2D diagram, but we definitely get the idea.  The ECU takes IN signals, and to compensate, sends OUT signals.  And of course, if it's getting BAD signals, it's going to send OUT some BAD signals to compensate.  Simple isn't it.  The hardest part (not saying it's that hard =P) in diagnosing a system is finding what can sometimes seem to be the needle in a haystack.  And when you get to working in cars, finding the hay in the needlestack (I have cut my hands plenty of times before working on engines, but of course I've got better at it).

Now of course it's always better work "smarter" than work "harder".  We want to a fiddle with the least amount of parts as possible, to a certain extent of course.  We are dealing with electronics, and if things go back in the wrong place, things can go bang. or in some cases a light smoke followed by the smell of melting electronics.