Holley Sniper 2 CJ Installation

Installing a Holley Sniper 2 on the jeepfan.com 1978 CJ-5 AMC 360 V8. A log time ago the jeepfan.com 1978 CJ-5 had a Holley Pro-Jection throttle body injection (TBI) on its AMC 360 V8 that worked quite well, until it didn’t. At that point the TBI was removed and an old school Holley Truck Avenger 4 barrel carburetor was installed with a Carter low pressure fuel pump.

The Truck Avenger worked pretty well but it really needed some professional tuning to get it correct. It always ran rich which caused fouled plugs and excessive exhaust stink. Five minutes spent standing with the Jeep would put that fuel smell in your clothes, hair and anything else. Originally the thought of simplifying the fuel system turned more complex and required carb tuning skills..which we don’t possess.

In 2025 there are a few modern throttle body fuel injection systems available notably the Sniper 2, FiTech, and Aces. If you do some research you quickly find they are all loved and hated by people. Just like almost anything on the internet, there are many many opinions. In the end after a lot of videos and research the Holley Sniper 2 was chosen. There’s a simplicity in design of the Sniper 2 and the additional availability of a Jeep specific in tank fuel pump is a huge plus.

It’s well known that carburetors do not like offroad and the terrain can cause a carb to act up. This is most obvious when going up or down hill. The angles can cause fuel to spill into the engine and cause a flood condition. The Truck Avenger is designed to minimize that with the fuel vent cross over tube so it was never an issue for us with this carb. But this may be the only carb out of the box ready for off road. With EFI this is completely eliminated and the engine will run properly in near any position.

Why the Holley Sniper 2?

The Sniper series has some time behind it, meaning that it’s been available and used for several years. The Holley Sniper 2 model adds some needed improvements, most notably signal interference protection and overall improved design.

The Sniper is a direct replacement for a 4160 style four barrel carburetor meaning it will bolt on to a standard square bore four barrel intake manifold like the Edelbrock Performer that was already on the jeepfan.com CJ. What’s interesting about the Sniper is that the “size” of the unit is not as prominent as four barrel carburetors since it’s constantly working to maintain the proper ratio of fuel to air. The documentation says it’s capable of flowing 800 cfm but that doesn’t mean it’s the same as an 800 cfm carburetor.

The Holley Sniper 2 uses 4 high pressure fuel injectors that inject fuel into the bottom of the throttle body. Several sensors allow the unit to adjust the fuel and air flow to maintain proper fuel to air mixture. The oxygen sensor probably plays the largest role of the sensors, reading the exhaust as it’s flowing past it. There’s a lot of technical stuff you can read online about the Holley Sniper 2, much of the nitty gritty details will not be explored here.

What we like the most about it is the “start it and drive” way it works. It can be fine tuned if you are interested in that but for the most part the out of the box setup will work great for most applications.

Many people argue about the “simplicity” and reliability of a carburetor, that could be debatable since anything can fail. We’ve never been scared off with some tech and in general the Sniper is considered reliable. Fuel injection has pretty much proven itself on modern vehicles.

This is a rather big project…

So it will be broken up into several sections.

• Out with the Old
• Parts List
• Installing the Sniper
• Wiring
• Oxygen Sensor
• Fuel Lines
• Tank
• Starting and Tuning

What we Bought (to start)

We had no sponsor type deal with this install so this was a straight up purchase from Summit Racing. Here’s the breakdown

Holley Sniper 2 Kit Holley Part # 550-511-3XX. This is the basic kit without a fuel pump or power distribution module.

Fuel Tank Holley Part# 19-510. The Jeep had a terrible plastic fuel tank in it that was difficult to fill due to the thick plastic fill tubes that restricted fuel flow. This is a Holley part number but it is essentially a stock 15 gallon CJ tank.

Fuel Pump Holley Part# 12-307. This is the Holley in tank high pressure fuel pump designed specifically for the CJ 15 gallon tank. This also includes a compatible fuel sending unit.

Summit carb spacer SUM-G1408. Since the CJ has an Edelbrock Performer manifold. The performer is a dual plane manifold and it seems common for people to use a spacer to open up the dual plane to get better performance from the Sniper. It seems that not running a spacer will work but we went for it.

Part 1: Holley Sniper 2 Installation

This install is pretty custom and you will likely have a completely different situation than us. But, the essence of what’s going on can translate well to other Jeeps and vehicles.

Put very simply this job entails: remove the old carburetor and things that went with it, replace fuel lines if needed, remove the old fuel pump. Install the new throttle body, wire it up, get the fuel system plumbed up, install new fuel pump. Test and tune. This project took several weeks and there was a lot of little extras that slowed progress.

Out with the Old – Removal of Stuff

We started with removing the Holley Truck Avenger carburetor. Disconnect the battery first. Vacuum and fuel lines were disconnected as well as the throttle linkage. The Truck Avenger had an electric choke with a 12V power supply. This will not be needed and was removed. If you need label your vacuum lines for reuse.

Make sure you cover the ports in the intake to avoid anything getting dropped down inside the engine.

The fuel tank was drained and was removed from the Jeep along with the 10-20 year old mud trapped with it. All of the fuel lines were removed since they were going to be replaced with all new line. The existing Carter electric fuel pump was removed. The engine in our CJ didn’t have a factory mechanical fuel pump since it was fuel injected in the past.

Wiring Mess

I take full responsibility of the wiring mess in the CJ. It’s not a total mess but it could be better, as I age I get more picky with it. Much of this isn’t part of the EFI but it just pictured for some entertainment.

Part 2 – Wiring, O2, Fuel System