I’m having an issue with my factory tach. When it’s hooked up the car starts on the release for the key and when it’s not hooked up the car starts on the crank of the key. If there is anyone with any insight on what the problem and solution might be I’d be very grateful for your info. Thanks!

 

This is the original Points Distributer?

 

yes it is

 

Problem may be ign switch as tach power is from ACC side and not IGN side.
Might hook up a test light for troubleshooting and compare results.

 

I'll bet the bypass (secondary) ignition wire at the starter isn't hooked up to the coil. This gives the coil a full 12 volts only while cranking. Without it, the ignition may not get enough juice to start because the main power supply to the coil is a resistance wire, dropping voltage below 10 volts when in run mode, and way less voltage than that when the starter is sucking power. Now add on a tach to the mix...