I have been having problems for about a year with my 1991 Z32 NA. It's been having kind of a rough acceleration and throttle response hesitation..just a little... I replaced battery terminals and battery, cleaned MAF, had fuel filter replaced in July, spark plugs replaced in September. I have a hunch it might be the FUEL PUMP because when I start my car, I can hear a whining going on behind the drivers seat for number of seconds, then it will cut off. then I'll hear the whining again when I press on the gas. When I accelerate the car will kind of rumble and shake the car..and when I brake or let off gas.. it will seem fine. I just hope its not a bad injector. Having to think I have to replace the fuel pump is headache enough. xD
Please reply if you have any responses as to what this issue might be?