Vacuum lines *DELETED*

[John G.]

Post deleted by John G.

[rocketraider]

Hopefully I can make this make sense. First, is the car's Transmission Controlled Spark system still intact? The TCS is tied into the thermo switch, and unless you're going for 100% concours resto or it's required to pass emissions visual inspection, I'd ditch the TCS.

<span style="font-weight: bold">PART 1</span>

On the ported vacuum switch itself:

Bottom port goes to an intake manifold vacuum source, usually a tee in the trans modulator vacuum line on AT cars or an intake vacuum port on SMT cars.

Middle port goes to the TCS solenoid on the intake.

Top port goes to the distributor vacuum advance.

The ported vacuum switch switches distributor vacuum between ported vacuum and manifold vacuum if the coolant temp gets up to about 220 degrees. Switching the vacuum source to manifold vacuum advances timing at idle to help cool the engine.

<span style="font-weight: bold">PART 2</span>

If you still have the TCS solenoid:

The vacuum port on the end with the wiring plug connects to a ported vacuum nipple on the carb (above throttle plates).

On the end with the right angle vacuum nipple, the port in line with the TCS solenoid body connects to a vent nipple at the top rear of the carb (there should be two nipples on a 1970 carb- one for TCS vent and one for choke clean air source).

The port at right angles to the TCS solenoid body connects to the middle (TCS) port on the ported vacuum switch.

The TCS solenoid delays vacuum advance to the distributor until the transmission is in high gear. Look for a round metal thing at RF of intake with wires and vacuum hoses going to it. It's notorious for failure and if it fails, you will never get any distributor vacuum advance. Meaning- rotten performance and gas mileage, and probable overheating. Meaning- your car's gonna idle funny when the PVS switches between ported and manifold vacuum trying to cool the engine.

<span style="font-weight: bold">PART 3</span>

If you elect to disable the TCS, simply connect the middle port of the ported vac switch to a ported vacuum source. The PVS will then function as described in Part 1.