Cars and Clients Stories
Open Search Panel

MGB Fuel Injection Tank and Lines

When installing fuel injection in any vehicle originally equipped with a carburetor, updates to the fuel delivery system must not only be considered, they must be executed. This article, situated in the direction of the MGB, works with engines sizes from 1.0 to 6 plus litres and can be used for both internal and external fuel pumps, filters and swirl pots because we do not give defined parts but only general guidelines.


  1. Using the late model pickup that comes out the sender that your tank already has (EARLIER TANKS CAN INSTALL THIS LATE MGB PICKUP IF DESIRED), start by removing the 1/4" fuel vapor line from the underside of the car. For our purposes, we will no longer be using this.


  2. Remove the sender/pickup from the tank- once out, remove the small screen from the end of it.


  3. Reinstall in the tank: I understand this is only a 5/16" line but if this is the only 5/16" line to feed the system, this short restrictor will function fine.


  4. From here, install a 3" piece of rubber line with fuel injection type hose clamps.


  5. using a 3/8" Steel pipe pushed into the 5/16" rubber fuel line, run to your fuel filter and pump.


  6. The 1/4" line that was removed earlier should now be replaced with a 3/8" feed line. This is best done with the driveline still out because the line goes up the firewall on the passengers side next to the original 5/16" carb feed line that will now be used as a Return line.


  7. With the 3/8" feed line in place and presuming the original 5/16" line to be reused as a return, there are several places in the system that the "new" return line can be used.

    • In older tank that had the feed line brazed to the right front corner of the tank, this can be reused as a return pending the small particle filter is not plugged. If this filter is plugged inside the tank, insuring all the petrol is out of the tank, place compressed air through this line when the tank is off the car should blow the filter apart on the inside allowing the fuel unrestricted return flow.

    • Tanks with charcoal canister vents may use this to return fuel to the tank. If this is done, insure your line is built in a way that if in worst case scenario, your fuel does not dump throughout the boot. It also helps to have a PCM/ECU that shuts fuel flow when the engine is not running such as the L32 3.4L V6 does.

    • Into an alternative location such as a pipe installed into the filler neck. There are some systems out there for this as well. It can work but the first two locations work well and have less potential costs.


  8. The last item on a fuel injected tank is a vent. If removing the charcoal canister(s), one should vent the fuel cap (where legal) or place a vent in the system. When the original vent for the charcoal canister (near the fuel filler neck in the boot) is no longer used, it is a good idea to place a line off this, straight up the inner wing (fender) of the vehicle by at least a foot upwards and then exit the floor. There is a plastic plug in the floor over to the side that can have a line popped through. Why drive the line at Least one foot upwards? Because as you accelerate, fuel sloshes back in the tank and will spill right out unless it has enough of a hill to climb. I prefer to make this hose run 18" upwards and then back down another 18" or more before exiting the vehicle.


Please note- always use high pressure fuel line and high pressure fuel hoses. Standard fuel line is rated to burst around 45psi and should only be used up to 15 psi lines. For fuel injection, hose should be rated for over 100 psi as fuel is nothing to mess around with if you value your life and the life of others around you.

If in doubt, seek a professional for hands on experience.

BMC offers a fuel injection tank with an internal fuel pump. This information is still relative as it speaks of building the lines to the system. If your tank is rusted, dirty or have question about a noisy external pump, take a look at our 18 gallon MGB fuel tank.