23 FebThe EFI Fuel Pump High / Low Pressure System
There’s a low pressure pump attached to the inner wing panel, and a high pressure pump built into a swirl pot, bolted to the boot floor with some mini exhaust bobbins. The low pressure feed is plumbed in, the low pressure return is about to be done – I’m just waiting on some fuel hose clips. Will put a glass filter on this return when it gets hooked up.
The high pressure return is shown connected (it’s the one at the top of the pump), haven’t routed the send yet. When I do I’ll be using a Sytec high pressure fuel filter on that as well.
Extra fuel pipe hole drilled, 1/2″ dia. just like the original one on the right. Waxoyl doesn’t half attract dirt.
The Spitfire 1500 fuel tank has a stub at the top (one on the right) which was used for all that smog recirculation stuff American cars had. It just happens to be an 8mm OD stub, perfect for 8mm ID SAE J30 R9 fuel hose. This is where the return from the swirl pot goes.
I was previously using this as a vent, I’d drilled a little hole in the blanking cap that the factory put on it, and even though the hole was tiny, fuel still would spill out when the car was topped up with fuel and driven off. You can see where spills have made a bit of a mess of the paint, will need to touch that up. I’ll now either need to put the old vented fuel cap back on, or figure out a way of modifying my locking fuel cap so it’s vented.