Spartan-Alteran

hay my 90 302 XLT wont start unless i add gas in the air intake but it only last 30 to 1 minute run time so i do got spark and i also hear a faint clap sound wen i do this is the engine clung or sum thing ?? is ben park for 2 years wen i 1st started it work well then all the student it just stop't the old owner told me he add a new engine and transmition just wen he did that he park it and now well i wana restore it but i cant get the engine to work well any idea's

mrslyfox

is the fuel pump kicking on? maybe the fuel shutoff switch tripped?