With the traditional Z32 hose clamps periodic re-tightening is required. This is because over time, especially during cold weather, the rubber hose shrinks gradually. As the hose shrinks, the tension exerted by the clamp is lessened, and eventually this progresses to a point where a fuel leak forms. For this reason, Z32 owners often notice a fuel smell during colder weather. This becomes extremely problematic with the short fuel hose joining the two halves of the fuel rail together, as its clamps are almost completely inaccessible without removal of the intake manifold. This can be extremely dangerous if left unchecked.
In 1997, Nissan gradually began switching to a new spring clamp of fuel hose clamp Part# 16439-16E0A .This clamp is able to the proper amount of tension on the hose at all times, even if the hose shrinks.