After replacing the fuel hose last year I took another look at the fuel system. As Judith doesn’t get used regularly the fuel drains out of the elevated section to the pump when she’s sat for a while. As the fuel pump is mechanically driven from the engine and it’s designed to move liquid rather than air this means that the starter motor has to run for longer than is ideal to get things going. To overcome this I’ve got a manual fuel primer pump and a clear fuel filter to check the flow.
As always when working with the fuel system, disconnect the battery before starting.
I opted to fit the primer pump down by the chassis rail where there is normally a metal tube connecting two sections of fuel line. As it’s lower than the tank, the section back along the chassis to the tank needs stopping up otherwise the fuel will empty out.
I fitted the primer pump in place of the metal tube but, as it’s longer than the tube, I also had to cut down the connecting rubber hose to the chassis fuel line.
There’s not much space in this section between the fuel hose clips on the top of the chassis and the one further back in the chassis leg. It took a bit of adjustment but the primer pump nestles in quite nicely and there are no kinks in the hoses.
Admittedly this isn’t necessarily the most practical location for the primer pump as it’s tucked away behind the wheel and exposed to the elements. However, it’s only going to be needed when starting after having stood for a while so having it tucked out of sight is the more pressing concern.
The second addition is a clear fuel filter between the pump and the carburettor. This literally gives a window into the fuel system so I can check if the pump is wet or if I need to use the priming pump to push the air through.
I removed a section of the fuel line, roughly the same length as the filter, shortly above the pump so the hose routing stayed the same. Given the proximity to the exhaust manifold I didn’t want to lengthen the hose here as the extra slack would increase the chance it would come into contact with the manifold with potentially fiery consequences!
With everything fitted, and the hose clips tightened up, a few good squeezes of the primer pump rewarded me with fuel clearly flowing through the filter and – just as importantly – no leaks.