A friend and I tested the fuel pressure on my 93z the other day. With the car in the Key on position I got around 35-39psi however in less than a minute it had bled down to 30 psi. Also with the car running I was getting about 39psi but when you give the car a quick rev it would drop a few psi and then quickly recover. With the vaccum line off the regulator it jumped to a steady 45 psi. Is this normal?

 

That is about right, you should always check it with the vacume line off. but all of them that i have seen drop a little when reved in park, But while you drive it stays steady. Did you drive it at WOT?

 

Fuel pressure should increase when you rev it. When was the last time the fuel filter was replaced?

 

I didn't have a chance to test it under load, only with the car sitting. So the drop is ok with no load? The fuel filter is about a year old, but I guess I could replace it.

 

Test it under load to be sure. Your drop from 39 psi to 30 psi after a minute isn't a problem.