I did a b16a swap in my 90 CRX DX and its running real rich. I have been trying to figure out why. I have been looking at different things on my engine and I'm kind of a noob at all this stuff, trying to learn on my own. But on the left side of my fuel rail there is a little plastic cover over a screw. I just noticed it and it looks like an adjustable screw. I wasnt sure if I turned this if it would effect my car at all. I dont know what the screw is, does anybody? I just bought a fuel pressure and vacuum pressure tester and I'm gonna try and check those. How do I do it, and what should the pressures be?

 

that little screw is on the pulse damping nut, which I am uncertain what it does but it has nothing to do with your running rich problem or fuel pressure

 

So what would happen if I tightened it?

 

probably nothing??

 

does anyone know what this screw is for?