Volvo Repair: 1979or80 volvo wagon starting problems, volvo wagon, toxic compounds

Question
my sons car starts fine, drives 15 minutes to my house, but wont restart...it will only restart again if Hes let it sit for awhile, like days, or at least HOURS...Hes not a mechanic, had alot of work done on it, we are stumped as to where to put money next...He isnt flooding it, was, but learned...it IS fuel injection tho...any ideas about sensors? or filters? that we may have missed? thanks for your help *smiles*

Answer
Hiya Granny...
         Well,I assume you are relating your question to a 245...B21 motor...
         My first guess is...FUEL FILTER.
       The job of replacing the fuel filter is somewhat of a difficult job...under car..connected to fuel lines that will leak if you make any bad connections...leaks ARE very bad...dangerous to life(super bad fumes,todays gas is loaded with toxic compounds).
           So Granny,drive the Volvo to a trusted mechanic and have them do the job....cost..$40 to 80 depending.
                         Bilbo