Help installing a tachometer on a 90 gsx

[GettinPaper]

I'm wondering where to tap the green wire for an rpm signal??
Any help will be appreciated.
It's on a 90 gsx by the way.

Thanks

 

[tsi1991awd]

Spark plugs or spark plug wires? They are two different things...

 

[NeMiZiS]

Oh yea I meant to say spark plug wires.
So it turns out she wasn't out of gas.
I put some gas in yesterday and still wouldn't start!
I found out I had no spark, then eventually I noticed that the plug that sends power to the coil had wiggled loose.
Plugged it back in and she started right up!
But now the tach isn't working again......