So I'm running a naturally aspirated '95 NA8 built on a MS3 basic and am wondering if I can cap off some vacuum line ports and remove the lines or if that would cause an issue ?




.) The EGR valve has 2 vacuum lines going to a solenoid mounted on the passenger side behind the OEM charcoal canister - afaik this solenoid is not controlled with a standalone and so the lines are just permanently blocked off. Should be safe to remove the lines and solenoid and just put 2 rubber caps on the egr valve ?
The pipe going to the exhaust header is removed and EGR valve has a blockoff plate.




.) There's also a vacuum line going from the fuel pressure regulator? to another solenoid (18-471C in the parts diagram) sitting between valve cover and intake manifold. Also not controlled with a standalone ? So should also be safe to just remove the solenoid and cap off those ports ? Or is that specific solenoid open in a non powered state ?



TIA

 

I removed the EGR valve and capped the hole in the manifold. Also capped the vac ports. I never removed the FPR solenoid.

 

TIL: Don't cap the FPR, it needs intake manifold vacuum to regulate. Without it I was suddenly running ~+10 rich over the entire map.
So I guess the default state of this solenoid is open to manifold and it's used in stock ECU NA8 to add fuel during a hot restart condition.

https://www.miataturbo.net/megasquir...d-59139/page2/

Next job, wiring it to a low side output to mimic the OEM hot restart procedure