Howdy, I disconnected my vacuum lines to my egr valve also some lines going to my heater control valve, my question is do I need to plug up these vacuum lines, or just leave them?

On a separate note I installed an aftermarket sensor that shows me the temperature of my coolant, it stayed at 190 pretty good while by stock engine temp gauge seemed to rise much higher than 190, and was fairly inconsistent, any thoughts? 1978 280z

Thanks a lot.

If you disconnect a vacuum line and it is sucking air, it needs to be plugged.

Curious, why are you removing vacuum lines?

Where is your aftermarket sensor connected? How is it connected?

I just put in an exhaust manifold and the egr is plugged on it, so I removed the vacuum line on the intake manfiold so the egr never opens, also my heater control valve was cracked, so I just ran a 90 degree elbow to my heater core, eliminated the heater control valve and disconnected the vacuum lines going to it.

MY aftermarket sensor is attached to coolant lines near my firewall right before the coolant goes in the heater core. It is attached with hose clamps, and has a temperature needle that shows the temp of the coolant as it flows by.

Thanks.