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Hi, right now i am in the process of fixing all small issues with my Fairlady. Since you guys already helped me I want to try my luck a second time. I had a look at the vacuum lines and to me they seem to be set up in a weird way. The car is a '78 280Z with a 280ZX engine (L28E F54 block with P79 head) converted to Ztherapy SU carbs and original AC. The engine runs fine apart from a slight fluctuation in idle speed (every 3-5 second it goes up from 800rpm to maybe 840rpm and then back down again). I checked all the FSMs to use the correct terms in my drawing and I added three pictures of the current situation. Especially the wrong plumming of the servo diaphragm and control valve +the missing connection to the carbon canisters vacuum signal line seems odd to me. If i understand the original piping correctly then I would expect that the servo diaphragm is doing nothing in this setup (have to check if it moves during let go of the throttle) and that the carbon canister is only doing its job in 'idle mode' due to the bypass mentioned in the haynes manual (because the valve for the purge line is never opened by the vacuum signal line). Another point is the missing of the EFI specific FCID. The AC is not working at the moment so i don't know if the car runs fine without raising the idle rpm. I wonder if it would make sense to pipe the FCID magnet valve to the control valve to use it as a 'carb FCID'? My overall question to the experts is 'Do i need to be concered about this vacuum setup (do i need the servo diaphragm/carbon canister to do their work) or is this maybe a clever solution?' Thanks in advance for your time and help. Picture 1: Picture 2. Picture 3.

After 2.5 weeks of waiting, my new carbs have arrived! I decided recently that I needed to kick start things with the Z and do something to get me excited about working on the Z again (although the sun coming out really helps lately), so I called up Ztherapy and ordered a new set of carbs and a new balance tube. Next week is dead week and finals the week after that, so it's likely that I won't be swapping anything till spring break. Until then I'll just have to enjoy looking at these beauties.