Fuel Pressure Reading Issues
 

I'm new to the site, Mustangs, and cars in general honestly but I've come across an issue that doesn't make any sense to me or the other more knowledgeable people I know.

I'm having issues with a couple misfires on a 98 GT that I recently purchased. I've gone down my checklist of possible causes trying to diagnose it myself but I ran into an issue when I tried to check the fuel pressure.

First time around I tried three different fuel pressure testers on my Schrader valve. All of them read 0 even when the car was on. So I immediately figured there was an issue with the valve. I purchased a new one from latemodelrestoration and put it on today. Still reads 0 while on. I'm stumped for the most part.

I did notice that all the fuel pressure gauges I've tried have required a special ford adapter for the valve. Without the adapter on the valve squirts gas like a fountain if I press the stem in. However when I press the adapter's stem (while the adapter is on of course) nothing comes out of it. So maybe the adapter is broken? I'm starting to think so but I've tried 3 different fuel pressure testers, one of which was at a local mechanic shop so I feel like they can't all be broken. (also the fuel pressure tester works fine on my 99 Durango)

Anybody ever had a similar issue? I'm going to the Ford Dealership Monday to ask them about it but I thought maybe some of you may have an idea or two.