So I'm close to getting my fd running today but there is a steel vaacume line that I can't identify. I'm at the shop with no net so I can't pload a photo but ill describe it, its a steel line that runs parrellel with a steel coolant line. They both run under the vacume manifold and coils. The end that I don't know where it goes sits on the driver side of the motor right above where it says 13b mazda on the foward rotor housing and just under the oil filler neck. I can be reached a 505_307_2902 if you call I can text a picture really hoping for a response as I'm very close to driving this home today thanks so much!

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/vacuum-diagrams-stock-simplified-sequential-non-sequential-single-turbo-749702/
check out the 1st vacuum diagram picture in the first post. that is for an unmodified sequential turbo system with all emissions intact. I think your talking about the red line which goes to the double throttle control actuator.

 

Maybe?

I think you may be referring to the crankcase ventilation line?

The line that crosses over the block and connects the nipple on oil filler tube to primary compressor inlet pipe.

It crosses over the block along with the oil feed line to turbos.

Ted