AOD TV Cable adjustment question

I installed an AOD in my 66 Mustang with a Lokar TV cable. I have a pressure gauge hooked to the tv port on the right side of the trans. center port and I have the cable block tool to install on the cable to make the adjustment. I have followed the Lokar instructions. It says, while in neutral, engine warmed up, engine idling, to install the cable gauge on the cable and the pressure should be at 35psi, then when you take the cable block tool out the pressure should be zero. Well I have 35psi all the time no matter if the block tool is in or out. I tried pulling on the cable while checking the pressure gauge and the reading doesnt change that much? Could I be doing something wrong?

Ok I found the throttle lever on the trans. was sticking and not letting the lever to return to its idle position. Now I have 0 psi at idle, but now I cannot get 35 psi with the block tool in. Even if I pull the cable all the out, the most I can get is 28 psi. Would it be possible I have a defective pressure gauge? It is brand new?