Nissan Repair: Nissan B12 1986/engine start, fuel pump, check valve

Question
what causes the fuel in the fuel pump to drain back to the engine causing hard start after engine has cooled for about 6hrs.

thank you.  

Answer
Evans,

The check valve in the fuel pump has failed.  Replace the pump and you should be fine.  But, before you do that be sure it is not the injectors leaking down after you trun the engine off.  If they leak down instantly, after the key is turned off, means they are leaking.  If this is the case replace the injectors instead.