Holley released their newest EFI systems, dubbed the Avenger and Dominator, about a year ago now.  They have been making waves across the street and strip world for its ease of use and expandability options.  To help people interested in the system or troubleshoot common installation questions, Holley has released a slew of videos on HolleyTV.com that helps out.

Main harness overview

The product line starts at the Avenger, which is a bolt-on-and-go EFI system that will self tune with a variety of pre-determined questions through the hand held LCD display. The self-learning ECU will give you the option to do some global spark and fuel tuning for idle and wide open throttle while also displaying an array of data from the sensors. This is a great solution for a mild to moderate street car setup.

The HP EFI is the second level on the Holley EFI line. Similar to the Avenger with its self learning capability, the HP adds four programmable inputs and four programmable outputs that are ideal for most vehicles with a single power adder, as well as laptop programmable tuning. This feature allows the user to configure the system to support a wide range of controls including boost control, progressive nitrous (up to four stages), water/methanol injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. Also this is a direct plug and play ECU for GM LSx applications. This is perfect for an aggressive street car or moderate racing application.

Wiring techniques

Connecting to power

Proper grounding

Finding 12 volt power

Avenger initial setup