ECU diagnosis and tuning for beginners.
Discussion
Be gentle with me, I know nothing about this subject,but it fascinates me.
I would like to learn about setting up the ecu/engine and learn how to tune, generally mess about with , diagnose faults etc.I know most cars can plug in these days.I am told for 1992 xjr I need couple of cables linking engine ecu to interface box to a pc with the right software.
Can you buy modern systems that do this and fault diagnosis these days or do you need the original software and cables etc?
Can you replace with modern aftermarket systems?
Are there any good books to read?
I would like to learn about setting up the ecu/engine and learn how to tune, generally mess about with , diagnose faults etc.I know most cars can plug in these days.I am told for 1992 xjr I need couple of cables linking engine ecu to interface box to a pc with the right software.
Can you buy modern systems that do this and fault diagnosis these days or do you need the original software and cables etc?
Can you replace with modern aftermarket systems?
Are there any good books to read?
Some OEM systems have been cracked so you can use software like efilive for GM apps to gain pretty full access to the ECU or you can run an aftermarket ECU which is designed for ease of use and management. (OEM stuff has a lot of maths and abstraction at times)
There are books around for sure. Check on amazon for "efi engine management" or similar.
Once you get your head around the basics, its pretty easy. The hardest bit is startup and idle, with idle being the worst.
Cruise is simple in comparison. You pretty much target stoich and MBT adding enrichment under heavy load.
Idle is a mess of controlling airflow as well as spark and fuel. Then throw in cams with overlap, higher loads on the engine through PAS or AC etc and sorting out a stable idle under all conditions, temperatures and loads can be pretty fun.
But its the most fun you can have with your car ever
There are books around for sure. Check on amazon for "efi engine management" or similar.
Once you get your head around the basics, its pretty easy. The hardest bit is startup and idle, with idle being the worst.
Cruise is simple in comparison. You pretty much target stoich and MBT adding enrichment under heavy load.
Idle is a mess of controlling airflow as well as spark and fuel. Then throw in cams with overlap, higher loads on the engine through PAS or AC etc and sorting out a stable idle under all conditions, temperatures and loads can be pretty fun.
But its the most fun you can have with your car ever

Dave Rowe is indeed Mr Motec, and he can also offer tuition classes on your ecu, or I guess any other topic along similar lines.
Although I'm sure a few simple books would give you a basic understanding
I think its maybe out of print now, but Julian Edgar's 21st Century Performance is a great all rounder.
Or with a lot of patience, check Autospeed's online articles as there is a wealth of great info there ( Julian Edgar again )
Not sure if its free now or you have to pay. I was subscribed for years, although I'm sure thats run out a long time ago, but I can still view the stuff.
Although I'm sure a few simple books would give you a basic understanding
I think its maybe out of print now, but Julian Edgar's 21st Century Performance is a great all rounder.
Or with a lot of patience, check Autospeed's online articles as there is a wealth of great info there ( Julian Edgar again )
Not sure if its free now or you have to pay. I was subscribed for years, although I'm sure thats run out a long time ago, but I can still view the stuff.
It's worth trying to read around and get a basic understanding of how an engine works (spark ign or diesel, very different!) and how that applies to the task of managing the air, fuel and ign timming (or air, fuel mass and fuel timming for diesel), and how these all interact and are affected by the various operating modes. Understanding the basic concepts of things like how the engines manifold volumetric efficiency is altered by manifold pressure (and the effect of throttle angle on MAP for instance) and engine speed are cruical to being able to effectively "tune" any engine. (we'll leave the complicated stuff like cam-torque actuated valvetrain positional control algorithms till later........ ;-)
http://www.megamanual.com/index.html
A huge collection of information on the design and installation of engine mangement systems. It's based around their project which is the megasquirt ECU but the principles and much of the detail apply to pretty much any modern engine management system. It does assume a pretty good grounding on the basics of engines and internal combustion.
A huge collection of information on the design and installation of engine mangement systems. It's based around their project which is the megasquirt ECU but the principles and much of the detail apply to pretty much any modern engine management system. It does assume a pretty good grounding on the basics of engines and internal combustion.
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