Throttle Body EFI System

© 1994-2000 Lynn Mosher and Al Lipper, Injection Logic


This is the newest version of our fuel injection system.  The design stage was completed in March 1999 and several prototypes have been constructed.  We expect the beta test stage to be complete in early 2000.  This design for ECU7 is available for commercial licensing, however it is offered free to hobbyists.  We have not yet decided if we will undertake commercial production of these units ourselves.  Since the prototypes have been constructed, minor changes to the design have been made - these will be posted to this site when they are finalized.

Go to the ECU7 page.


Welcome to ECU6, last year's throttle body injection (TBI) system for vehicles that were previously carbureted.  Please note that while this system works quite well, it is not a complete and debugged fuel injection system.  For someone with a strong background in digital electronics, 8051 programming and BASIC, it is nearly complete, but still requires many hours work before it will be a fully reliable system that operates under any circumstances.  As its name implies, it is revision 6 of the system.  I have driven a ’78 Pontiac Trans Am with a 428 engine about 100 miles over the period of six months with this system, and it has also been fitted to a ’57 Corvette.  What I’m saying is don’t think you can solder together a PC board, plug in some sensors and start driving.  However, if you have a background in this sort of thing, then you will find great potential in the system.

One of the key features of ECU6 is it's ability to learn.  In theory, it can be installed on any vehicle and with only one or two coarse adjustments, the system will be driveable.   Next, the vehicle is taken through a series of special driving procedures (like normal cruise, rapid acceleration, etc.) and it relatively quickly adapts to the  vehicle's requirements.  Ultimately, it should be tuned well enough that it provides far better performance, mileage and emissions than a carburetor could ever be capable of.  Of course, if the user wants to manually enter values for the calibration, that may be done easily.  The calibration table can be modified via an Excel spreadsheet incorporating nearly five hundred data points for the fuel map alone.

The system is based on an Intel 80C51GB microcontroller incorporating 36 I/O ports, an 8-channel A-D converter and two programmable counter arrays.  It utilizes 64K of RAM and 64K of flash memory (though 128K chips are used because they are cheaper), a failsafe watchdog timer, serial interface for a PC and several other major features.  Sensors used are: MAP, Coolant temp., TPS, Oxygen as well as engine RPM and vehicle voltage.  Control outputs are for two sets of independent injectors, Idle speed control motor (IAC), fuel pump, oxygen sensor heater and one spare output.

 Download All ECU6 Files

ReadMe File (Included in Download All Files)

Photos of the completed ECU6 (About 700K)
 If you have built one of these systems and have ideas or questions, please feel free to contact me.  Although these designs are intended as a commercial venture to be sold to interested manufacturers, I have made them available to EFI enthusiasts without cost.  In any case, feel free to do what you want with the software and hardware plans but, YOU MAY NOT SELL ANY OF THIS INFORMATION OR ANY PRODUCT INCORPORATING OR BASED ON THIS INFORMATION, AND IT MAY IN NO WAY BE USED FOR PROFIT!  And naturally, neither I nor my company (Injection Logic) are responsible for the consequences of what you do with it.  I retain the rights to both the software and hardware, but have chosen to share this information, as I believe that greater potential exists among people when information is shared rather than withheld.  Cooperation is far better than competition.  Good luck!

Viewing PCB board Gerber files
If you are not familiar with Gerber format files, they are one of the standard formats used by the PC board manufacturing industry.  A free Gerber viewer/printer may be downloaded from (or, for a better viewer, use (Note: this link appears to be dead).  However this does not print unless you pay for this capability).

Al Lipper
(805) 544-4636