Still not running right, i think

I have been working on my GP for a few days now, replacing a bad starter and some seals and fixing some leaks. Now i have a new problem. I have put the engine back together and now it will start up and run, but it will die when the gas pressure reaches a high level. I have a pressure gauge tool to measure this and it is reaching 80 on the gauge, shouldn't be going that high i think because the engine cuts of at 80 on the gauge, it averages 50 when running right. It will just jump to 80 randomly, it seems, and shut off. I put a new battery, starter, harmonic balancer seal, and some more seals and gaskets. Now it will run, but only after i release the pressure from the fuel line with the gauge tool. I don't know exactly what is going on or what could be causing it. Could anyone give me some tips, the 3.4 isn't the easiest to work on.

sounds like a feul pressure regulator that isnt bleeding pressure back to the tank, you might want to test the return system

also what is the fuel pressure, key in on position but engine off, anything over 55psi and you may have a regulator/ return problem

the engine cutting out could be from the engine running too rich, does the exhaust go black as it cuts out?

I agree with the fuel pressure regulator theory. The fuel pump runs constantly fromt he time the car is started until it is shut off. The fuel pressure regulator closes under heavy throttle (low vacuum signal) to keep the fuel from returning to the tank under high demand, and opens to allow it to return under light load (high vacuum signal). Before changing it though, check for vacuum at the regulator, as a cracked, disconected or collapsed vacuum hose will cause the same symptoms as a bad regulator. My system is to always try the simple, cheap stuff before changing expensive parts.

were there two different engines in 93 SE's?? mine has a 3.1L...

Alright I'll check for vacuum leak problems, it has had vacuum leaks before, and when i was puting the engine back together i did find a collasped vacuum hose, which i fixed. I'll check it out before i spend more money, thanks for the help. Yeah, and about the engines in the early 90's SE's they made a 3.1 multiport FI, and a 3.4 Twin Dual Cam V6 which was optional with the Aero performance package.