ECU/Harness Kits

Welcome to the ECU/Harness Kits page. This is where the big boys play. To be sure, there's nothing wimpy about any of the kits listed in the other pages in the Holley Fuel Injection Kits category. They're all incredibly capable of producing impressive horsepower and controlling a broad number of functions in addition to fuel and ignition.

"So why", you ask, "is this the big boys page?" Because this is where you find yourself when you realize there is no bolt-on, ready-assembled kit for your requirements. Maybe you need more horsepower than the 2-bbl and 4-bbl TBI Fuel Injection Kits can handle, and you're not running a small block or big block Chevrolet so you can't take advantage of the Multi-Point or Stealth Ram Fuel Injection Kits. Then this page, and indeed the resources of this entire website, are intended to give you all of the assistance you might require in building a fully programmable Holley Fuel Injection Kit for your particular engine.

Let's waste no time and jump right into the process you'll need to follow in building up a custom fuel injection kit for your application. As you read through this, remember that we are as far away as email, phone, or chat to assist you in the process. Let's get started!

Steps 1 and 2: Choose Your ECU and Main Harness

While we offer the Avenger ECU below, it is simply intended to be a replacement for a damaged Avenger ECU from and Avenger Fuel Injection Kit. The Avenger kits are great, in that they are ultra-simple to program. However, part of that programming process is selecting the kit of which it was a part. The setup program is not made to work with a custom fuel injection kit, so the Avenger ECU really isn't an option.

So, that simplifies the choice. Choose between the HP and Dominator ECU. You can read about the differences between these Holley ECU's at the Holley Fuel Injection Systems page. If you're not ready to do that much research, know that the HP ECU is an extremely capable, fully programmable ECU and will do nearly everything the typical owner would want. The Dominator ECU takes extremely capable to a whole 'nother level, and does anything even the most demanind professional racing team could want.

If you go with the HP ECU, you get the option of selecting from a number of ECU/Main Harness kits. By purchasing these together, you get exactly the harness you need for that given application and save a bit of money over buying the individual harness components. These kits include the ECU Power Harness, which is separate from the main harness. The plug-and-play kits connect to factory coil harnesses and all factory sensors. Choose from these Harness/ECU Kits:

HP EFI ECU and GM TPI Harness Kit: Plug-and-play Holley EFI for GM TPI engines
HP EFI ECU and LS1 Harness Kit:Plug-and-play Holley EFI for GM LS1 Engines
HP EFI ECU and LS2 Harness Kit:Plug-and-play Holley EFI for GM LS2 Engines
HP EFI ECU and Universal V8 Harness Kit: A pre-terminated solution for other V8 owners
HP EFI ECU and Universal Unterminated Harness: Use this kit if you're not listed above!

You can build any of these kits with the Dominator ECU by purchasing the Dominator ECU, Holley ECU Power Harness, and Main Wiring Harness separately.

Step 3: Choose Your Injector Harness

Depending on your engine, the correct choice should be obvious:

Universal 4-Cylinder Injector Harness
Universal 6-Cylinder Injector Harness
Universal V8 Injector Harness
LSx Injector Harness
Dual Holley 4-BBL TBI (Coming Soon!)
Unterminated 16-injector Harness (Coming Soon!)
Unterminated 24-injector Harness (Coming Soon!)

Step 4: Choose Your Ignition Harness

These deserve a little more explanation, so we'll do that.

(A work in progress...will finish ASAP!)

Step 5: Choose Your Fuel Injectors and Fuel Pump

We won't try to explain this in depth here, but you will find a detailed explanation on how to select the right fuel injectors on our FAQ. For multi-point fuel injection you'll typically want one fuel injector per cylinder. If you have an extreme application, and if your intake manifold has additional injector ports, you may need two or more fuel injectors per cylinder, but that is going to be very rare. Whatever you need find them on our Fuel Injectors Page.

Long before we created the greatest Holley Fuel Injection website on the Internet, we created the greatest EFI fuel pump website on the internet: Fuel-Pumps.Net. Rather than try to recreate that website here, we'll refer you that direction. If you are starting with a vehicle that was originally fuel injected, you can find a high-performance fuel pump for your application. Or, buy a high performance inline fuel pump that will work in place of your stock carburetor fuel pump. Remember that while they are both CyberAuto websites, they are separate so you'll have to order parts from each separately.

Step 6: Choose Your Sensors

Typically, a minimum configuration of sensors includes a throttle position sensor (TPS) and a wideband oxygen sensor. Highly recommended is an intake air temperature sensor and coolant temperature sensor. It will also make your life much easier if you get a pair of liquid pressure sensors for fuel and oil pressure. And if you're going to run a turbocharger or supercharger, you'll need a MAP sensor. Except for the crank angle sensor, You can find more information on the sensors you need on our EFI Sensors Page.

What's Next?

Beyond this, everything is optional--and the sky is pretty much the limit. A few of the things to think about:

Distributorless Ignition System (DIS): If you have a distributor a DIS is not required. You can pick up ignition timing from the distributor and use it to get spark. But for programmable ignition you will need a DIS.
Nitrous and Boost Control: As incredible as programmable fuel injection is, you haven't even tapped the maximum capability if you're not controlling your nitrous and boost with it. Control up to four stages of progressive nitrous!
Water-Methanol Injection: If you're running boost and are not familiar with the benefits of water-meth injection, let us introduce you! Increased horsepower and enhanced engine life are just two reasons to add this.
Gauges and LCD Touchscreen: Welcome to a whole new world of flexibility. Besides being bright and beautiful, the Holley Universal Gauges are just that--allowing you to display any of a huge range of engine parameters such as pressures, temperatures, and more. Or step all the way into the future with a LCD Touchscreen that lets you reconfigure the display on the fly!