High line pressure

[HotSpark]

Update 8/8: added a few pics below.

Curious what issues would cause line pressure to be 175PSI at idle without TV cable connected and in Park? While at idle and I pull the TV cable I can easily max out my 300 PSI gauge. I thought it may be a gauge issue but second gauge read identical. While running I attempted to pull the TV and let go about 10 times thinking maybe the tv valve was stuck but it didn't break loose so transmission is out.

The symptom that lead to me checking the line pressure was while driving down the highway I got on it from a roll just before getting to the exit to go to my house. Shifted great during that run but as I attempted to take off from the stoplight when it went into second it seemed like it was slipping bad and actually saw the RPMs go to 4500 before letting out. 1st gear seemed fine so I drove the final 2 miles on the shoulder to my house. Just curious what suggestions you might have for me to watch for. I have the transmission out and pump removed but haven't started taking any of the valves out.

Good news is the pan was clean and fluid still nice and bright red without having a burn smell but something was for sure slipping.

 

[bison]

The TV plunger spring is likely too long


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[David Husek]

The symptom that lead to me checking the line pressure was while driving down the highway I got on it from a roll just before getting to the exit to go to my house. Shifted great during that run but as I attempted to take off from the stoplight when it went into second it seemed like it was slipping bad and actually saw the RPMs go to 4500 before letting out. 1st gear seemed fine so I drove the final 2 miles on the shoulder to my house. .

What you have experienced pulling away from the stoplight was a second gear start. The engine will push against the converter and feel like the trans is slipping as the car feels real heavy to throttle input. Second gear starts will be a constant at the line pressure you have at idle. As bison stated, the TV plunger spring is too long or you may have a problem with the PR circuit. To prevent a second gear start, you can put trans in neutral when stopped then back into drive and you will be in first again. This is not a fix, but a good prevention to a second gear start at the track. I don't think you needed to remove the trans but it can't hurt to check.

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[HotSpark]

Adding a few pictures. Notice the red arrow in the valve body pointing to that little 1/4" cap sitting sideways. I added some measurements of the spring and the spacer I wasn't sure if that is stock. This is a KZ3 Valve Body.

 

[David Husek]

Remove the spacer, that is most of your high line at idle. The TV spring looks to be from a TV made easy kit. I am making this statement based on length and one I just installed for a customer. I would change the spring to a stock BR or one a little longer than a stock BR depending on throttle body being used assuming it is installed in a Turbo Buick. The cup plug in the valve body is a 3-2 control mod. It is put there to keep the valve open.

 

[bison]

That spring is a little long also. You will have to reduce the slack on the TV cable but still be sure you're able to bottom out the plunger. Using a gauge is the best way. 110psi is a good baseline as long as pressure rises briskly when the throttle is opened


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[mikestertwo]

Someone put that little cup plug in the valvebody to hold the line bias valve open.