Robin, I have had fuel problems with my 240z as well. I had dropped the tank, cleaned and sealed it, replaced the fuel pump, checked the fuel lines on my car, and the carbs, all was good and clean. However, when I start my car it is starved for fuel for about 20 seconds, then fuel comes gushing out. Further research showed I had a cracked and broken fuel outlet line on the top of the tank. Anyways i would suggest checking for sufficient fuel pressure, or just go ahead and get a new fuel pump. Mine "gumped up" from junk in the tank, and a new one only cost about $28.00. I also added a second filter on the car next to the tank, that way I can see if i still have a dirty tank or dirty lines. That's my 2 cents on the topic.