This spacer allows the lift pump to operate in the middle of its possible travel.
Using a 4mm spacer allows it to be fitted without interference with the high pressure diesel lines to the injectors. Precision laser cut from aluminium, with gaskets and bolts.
Lots of people have asked what the benefits are to fittng a fuel spacer. The upshot is, adding a fuel spacer will elongate the life span of the pump.
Fuel pumps fitted to many diesel vehicles tend to snap their operating linkage, causing the vehicle to come to a stop.
Land Rover Tdi engines can still run (in the short term) with a broken pump but will experience symptoms of the vehicle being pretty poor starting from cold and you’ll probably get fuel starvation up hills. The pump was originally designed to have a spacer but appears to have been left out due to a cost saving exercise.
Most people do not realise the pump is damaged until they attempt to change the fuel filter – You try to prime the fuel filter using the priming lever and nothing happens. This is because the pump is damaged. It has been operating right at the top end of its travel, causing strain. You then have to turn the engine by hand to find the one spot on the cam where the priming lever will operate. By adding the fuel spacer, it allows the lift pump to operate in the middle of its possible travel, thus causing less strain. The priming lever should then operate regardless of the camshaft position.