Ok i just bought a 1990 4Runner like a month ago, with 73K miles. like a week after i bought it . It pop an antifreeze hose in the rear of the engine. So i had to remove the intake manifold. fixed the hose, new gasket for the intake. it was good for like a week and there was a very strong smell of raw fuel. So removed the intake manifold again. the gasket had a leak so i rotated it . Put it back again . ran good for a week. Same raw fuel smell. So removed it again i just got a new gasket. Put it back again. Worked good for like a week. So now i can just smell it when its at idle. i rev it up and the smell goes away. The injectors look good no leak. Checked the fuel lines they look good no leaks. So now i dont know what to do..
It a 1990 Toyota 4runner V6 .

 

Just a guess but maybe your cold start injector? My guess based on the fact that you said it smells at idle and goes away when revved up.