I have a 1991 Nissan 240sx wirth 37000miles on it. About once a month it begins to stall and wont take gas. This occurs in all types of weather and usually after driving 5-10 minutes in the morning after starting fine. I have dicovered that if I open the gas tank and release the vaccuum that seems to be there the problem disapears almost immediately. I used to pour dry gas in thinking it was water in the tank and then discovered that taking off gas cap solves the problem. Its been tuned up and new fuel filter put in etc...since problem is not there when I take it to mechanic he cannot find the problem. Any help would be appreciated.
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Responce:

First of all, Congratulations!  A 91 240 with only 37K, man wat a sweet deal!   My 90's got 104.9k as we speak...  Normally I would think right off the bat, that you've got problems with the warmup regulator (Coldstart valve?).. (I'm not sure what Nissan calls it but all fuel injected engines have one in some form, it's the equivalent of a choke on a carbeurator).  But, since you mention the vaccum release deal with the gas tank, I'm thinking fuel pump. BTW, what made you think to let the vacuum off of the gas tank? was it just by chance? also, does this problem occur all of the time or more often when the tank is low or near empty?  Sounds like the fuel pump might have some issues, as far as I know it's mounted in the gas tank.  Anyone? back me up?   Folks on the list will surely flame me if i'm giving false info ;-)  I don't know if your on the email list or not but you can subscribe by sending a message to: [email protected] with the subject header: subscribe be warned though that the daily posts average between 30-60 messages-- lots of cool people and good info on the 240!  get back to me, I'll research it. later,
                            -JT
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