I'm missing on one cylinder.
My troubleshooting went like this:
Pulled the injector connectors off one at a time. After pulling a connector the engine slowed noticeably on each cylinder. So I'm thinking each injector is working.

Next I pulled the plug wires off one at a time. I found one plug that when deprived of spark made no change on the engine at all. So I thought I found a fouled plug.
To find out if this plug was fouled I pulled it out and grounded it and had someone turn the engine over. The plug was sparking.

So I'm stumped

Any ideas?

 

Is it #5?

 

Having spark and having enough spark are two different things. If I remember right the proper test is to hold the coil wire 1/4 inch from the body and see if it sparks.

 

It could be a marginal plug. I'd swap with another one and see what happens. Also inspect inside the dizzy cover for carbon tracks. remember the electricity follows the path of least resistance. You might also try firing up the engine in a dark garage to see if you see sparks where they shouldn't be. The voltage needed to jump the plug gap is higher under compression pressure than atmospheric when laying on the block.

 

Marginal plug it is. Miss followed the plug. Off to buy a new NGK.

 

Update:
Replaced the missing plug and it doesn't miss!
YES!
Except a little at high rpm (above 4k) when under load. It feels like it's not pulling like it should and I think it's missing a little. It's hard to tell because the car is so quiet now since I re-did the interior. Also the rear diff whines like crazy.
Maybe I should replace all the plugs again?
It runs SOOOO much better now.

 

I got all 6 of my NGK plugs for $12 so I'd say it's well worth it!

 

Yea I'm going to do it but I want to replace the thermostat 1st. I think it's stuck open because the temp gauge never quite gets to the 1st normal line.