Gas Smell After an EFI Conversion? Why It Happens and How to Fix It

Fuel injection conversions are one of the most popular upgrades for classic cars and trucks. Better starting, smoother running and improved drivability are all great reasons to make the switch. But a lot of owners notice something unexpected afterward: the car still smells like gas, or even smells worse.

Why EFI doesn't automatically fix gas smell

An EFI system changes how fuel is delivered to the engine. It does not change how your fuel tank vents. If your tank vents to the atmosphere, fuel vapor still escapes every time the fuel warms up, whether you are running a carburetor or injection.

Many EFI conversions also add a return line and an in-tank or external pump. That means more fuel moving through the system, more heat going back into the tank, and sometimes more vapor.

Check every new fitting

EFI systems run at much higher fuel pressure than carbureted systems. A fitting that would never leak at carburetor pressure can weep under EFI pressure. After any conversion, inspect every fitting, line and connection, especially at the pump, filter, regulator and fuel rail. Fix any leak immediately.

Controlling vent vapor on an EFI build

If the system is tight and you still smell gas, the source is probably the tank vent. Vapor Trapper is a billet aluminum charcoal vapor canister that installs in line with the fuel tank vent hose. It captures vapor in activated charcoal before it can escape.

Vapor Trapper works with EFI systems, fuel cells and custom builds. Its universal design handles practically any inlet and outlet configuration, so it adapts to whatever tank and vent setup your conversion uses.

Pair performance with comfort

You did the conversion to make your car better to drive. Getting rid of the gas smell makes it better to live with. Add rechargeable charcoal, 6061 billet aluminum construction and a lifetime warranty, and Vapor Trapper becomes one more upgrade you install once and stop thinking about.

Shop Vapor Trapper at vaportrapper.com.