Begin by inspecting the contents of your Holley Sniper Master Kit. Make sure all necessary fittings, hoses, sensors, and wiring harnesses are in the box. I will try and make this series of posts and videos as thorough as possible so you can make a better-informed decision on fuel injection and understand the build process from a real perspective. I am installing this Holley Sniper EFI kit in a regular garage with regular tools on a regular old mustang. No tricks, special lifts or unrealistic fitment will be done to make this look easy. This is the real-deal raw installation of this system.
Holley makes it very easy to get started on this installation. This first stage is the Fuel Tank removal, installation of the fuel return bung (Russel Part Number: 670850) and the fuel pump and pre and post fuel filters. The photos below will tell the story and the video will serve as a great reference build resource.
I began this installation at the back of the car. I wanted to begin with the source of the fuel system and work my way up to the engine bay. This stage of the project is the most critical. You need to plan this phase out and ensure the fuel tank is in good clean working order. Make sure you notate the locations of your fuel sending unit and how much clearance you have to add your return line. This photo shows the back of the Mustang prior to removal of the gas tank. Fuel pump drain in place
To drain the fuel, I purchased a cheap inline electric fuel pump and attached it to the outlet feed of the fuel tank. I added a switched 12V source to the pump and let the pump run. This drained all of the fuel from the tank so I could safely lower the tank down and not spill any fuel on myself or my garage floor. wing the custom fuel tank drain pump removing all of the old nasty fuel from the fuel tank. Purchase the pump here for $11.99 Click Here
Showing the custom fuel tank drain pump removing all of the old nasty fuel from the fuel tank
A photo of the old nasty fuel being drained into the auxiliary fuel tank for disposal. This stuff stinks! Make sure you are in a well-ventilated area!
These are the fuel tank strap bolts. Loosen them one at a time leaving them threaded on just a bit until you are secure in your position to let the tank down slowly. Failure to do this may result in an unwanted explosion or worse, your pride and ego may be ruined when you drop the tank on your head accidentally. 🙂
More photos of the gas tank strap system
On 71-73 Mustangs. The fuel filler neck needs to be loosened so the filler neck can be pulled out of the fuel tank collar. These steps are critical. Failure to remove the filler neck prior to lowering the fuel tank will result in bending the rear apron of the fastback.
View of the inside of the trunk exposing the fuel filler neck inlet to fuel tank.
Lower the fuel tank slowly making sure you are free from loose fuel lines, brake lines, and kittens.
This is what the filler neck port looks like on a 71-73 mustang. This fuel tank is only bout 3 years old and you can see the buildup of the nasty varnish ethanol fuel creates when left to sit.
I started the deconstruction of this tank by removing the collar of the fuel tank vent and vent hose. YOU CANNOT USE YOUR VAPOR VENT AS A RETURN PORT. DON’T TRY IT! This has been verified via Holley technical support. If you try and use the vent port as the return line you will explode your fuel tank resulting in a ruined car and ego. Don’t do it!
Tighten the fuel return bung into the tank while holding the nut with a 7/8″ wrench
DONT FORGET: Add a downline from the newly installed fuel return bung into the tank. The hose should fall approximately 1″ shot of the very bottom of the tank. More on this here. READ THIS POST! CRITICAL!
DONT FORGET: Add a downline from the newly installed fuel return bung into the tank. The hose should fall approximately 1″ shot of the very bottom of the tank. More on this here. READ THIS POST! CRITICAL!
