Hello,

I was removing my exhaust manifold today to install a header on my '87 N/A Rx-7. Well I found two vacuum valves were in the way of the top bolts of the header. In the factory book they are described as either Split air solenoid valves or port air solenoid valves (can't tell which they are). It looks like they are vacuum actuated valves which control a flapper in the intake manifold. It looks like an emission part, and I found one was comletely seized, and I had to bend the small rod on top of it to get it out.

My question is will the lack of these valves effect the normal operation of the engine? One is spent, and I would just assume keep them off if at all possible.

Thanks,

Brian

 

One is a check valve which affect your emmission (if applicable in VT). Another one goes to air control valve.
Figure.

 

Those aren't emission controls, they're the actuators for the auxillary ports. Look in the manual under 6-port Induction System. Sounds like you need to replace them both. They should move freely, and rotate the sleeves in the intake manifold. Absolutely. If they're stuck closed you'll be losing a chunk of power at high rpm; if they're stuck open you'll be losing a chunk of torque at low rpm.