http://pengaru.com/~swivel/cars/rx-7/vacuu...uum_diagram.jpg



the dark green one, goes from the throttle body to the LIM, side closest to the engine, I think that nipple has a passage that leads to the primary injectors?



What's the purpose? Is it required for proper operation?

Umm? That diagram doesn't look like one for a second gen. Are you sure you have the right diagram? Mine only shows 3 soleniod valves(no EGR soleniod valve) and has a second line coming from the LIM going to the primary fuel rail. BTW this is my stock diagram out of my manual(90 shop manual).

I'm pretty sure it's the right diagram, it's for the S4 NA (87 GXL), but looking at my LIM the vacuum nipple on that side is centered between the primary ports, in the diagram it's kinda offset, but that may just be a mistake in the illustration. Yours wouldnt show an EGR valve etc because you have an S5 (90). The EGR was eliminated then...

i knew what that was at one point, i had asked the same question. I can't quite remember. That is the right diagram for you car though.

i dunno, they all have hoses like that, i'm thinking it equals out some kind of pressure wave?



mike