EFI conversions have been available from the aftermarket almost from the time EFI systems became universal as OEM equipment. Over those years, the systems and their software have undergone continual refinement, with better components and more capable electronics, as well as improved software. The goals in this development process are qualities that anyone can appreciate—reliability, tunability, and flexibility over a broad range of applications. The sophistication of today’s stand-alone engine management systems has reached a very high level.

At the end user level, however, it is helpful to consider the motivations and the expectations of the enthusiast considering a conversion to EFI. For starters, one might ask just why a guy might consider trading in that reliable old carburetor for an admittedly pricey EFI system. In the realm of normally aspirated high-performance engines, the usual objectives are to achieve the same kinds of advancements in efficiency and driveability associated with a modern car. Turn the key, and it fires right up. Run up to a light and it will idle without loading the plugs or requiring the old two-foot peddling to keep it running. Basically, the ideal fuel injection system promises the dream of putting away the jet kit and screwdrivers, with the expectation that it will perform under a variety of conditions with minimal attention. The capability of achieving these goals has been built into the systems for several years now, but achieving that level of execution is often another story.

EFI has spawned a whole new breed of hot rodder as an answer, a guy who just didn’t exist back in the day: the “tuner.” Armed with a laptop and a dyno, this cat works the fuel and spark tables, and the various other tuning offsets to really dial in an EFI system. The problem from an enthusiast’s point of view is that tuners and dynos cost money, and most end users are not “tuners.” Needless to say, hiring a specialist to “tune” an EFI system adds considerably to the time and money needed to optimize an EFI system, and even then the results will vary with the competence of the guy working the keyboard.

From a practical standpoint, for the vast majority of enthusiasts considering an EFI conversion, the ideal situation would be the ability to just bolt on the hardware, wire-up the electronics, and then hit the streets. This is where the latest technological trend in aftermarket EFI system seems to be centered. Enter the self-compensating or self-learning EFI system. The goal here is to largely take the rigorous tuning process out of the aftermarket EFI conversion by having the system tune itself. Here we take a look at three popular new-generation EFI systems, and the logic behind each.


Fuel Air Spark Technology (FAST) has long been a leader in EFI conversion components, and when the conversation shifted to end user–friendly systems, FAST’s answer was the EZ-EFI system. As the name implies, the objective with the EZ system is to make the conversion to EFI as easy as possible. To that end the real change is in the ability of the electronics to self-tune. The premise is to allow the installer to simply bolt on the components, and follow through with a basic setup procedure on the included handheld display, and the system will take the fine-tuning from there. The electronics look at the targeted air/fuel ratio and adjusts to those requirements through what is a very involved set of parameters in the unit’s programming itself.