Nissan Repair: Fuel Problem or ????, fuel pressure gauge, 1990 nissan 300zx

Question
Several days ago when I cranked my 1990 nissan 300zx it was idiling rough and after driving it down the road it cut off twice. After the second time it would not crank. I had it towed back and it sat for 2 days. The 2nd day it cranked again but once again idled rough, it would not stay cranked unless I continued to give it gas. After about 30 seconds it smoothed out and idled perfectly for about 8-10 mins. Without warning it suddenly cut off and would not start again. Im wondering if maybe Im having a fuel problem? Any advice will help. Thanks

Answer
Nick,

Check the fuel pressure as it sounds like the pump is going out or the relay is defective.  Get a fuel pressure gauge and screw it into the rail and check the pressure with the key on.  This will let you know if the fuel pump is working and when the key is off the pressure should stay a while.  If it drops to nothing really fast then an injector or two are leaking.