I wanted to change our 351w 1969 Mustang from a 2 barrel carburetor to a fuel injection system. There were a few different reasons for wanting to do this.
1: Fuel injection is more dependable and easier to start. While the 2100 2V Autolite carburetor is a very stable and reliable fuel delivery system, it still suffers from the problems inherent to any carburetor, difficult cold start / warm-up, and inconsistent air/fuel ratio control. These issues can be eliminated by a properly tuned electronic fuel injection system.
2: Power and fuel economy. With a good EFI system it is possible to have the best of both worlds. They can be tuned to achieve the best balance of HP and MPG.
3: But the main reason for the project was educational. Although I was knowledgeable about automobiles built in the 60's and 70's, I felt like the changes in "engine management" that started in the 1980's were leaving me behind. The best way to learn about the advances in automobile technology was a "hands on" - "do it yourself approach" of upgrading the Mustang to EFI.
I probably would have installed a factory ECU and intake system, but because the Mustang had a 351 Winsor engine, the choices of fuel injection systems available from Ford were limited. By the time EFI became common, the 351W had became primarily a truck engine. The intake manifold used on the truck engine was very large and not well suited for use on a vintage Mustang. I also wanted the option of modifying the computer program for better performance. While researching the options available to me, I learned about "Megasquirt". It is true 'do-it-yourself' approach. You build the engine control computer from a kit. It uses common OEM sensors, and the computer is fully adaptable and user programmable to work with almost any application. While definitely not a bolt-on system for beginners, it was perfect for my "educational" project.
Below is an outline of the system I am currently running.
MegaSquirt MS1 V2.2 running the 'extra code' with a modified relay board.
Holley GM type 2 barrel throttle body injection with two 85 lb injectors, adapted to stock intake.
GM water temperature sensor - GM air temperature sensor.
1986 Ford Van (E2000) external electric fuel pump with 5/16 pressure line and 1/4" return line to tank.
An Idle air control valve from a 98 Mustang, used for warm-up fast idle only.
This system could be used with a 60's chrome air cleaner to retain a stock appearance
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Here is link to the manual on the MegaSquirt web site.