Hello,
I have and old 91 GP SE 3.1, I haven't moved it much since I bought a 98 GTP 3 months ago. I turn it on every now and then, but it's not working properly once it gets a bit hot. It's seems to be tossing a lot of gas out the back. I've recently replaced the spark plugs, spark plug wires, air filter and checked and replaced the vacuum lines for the MAP sensor and fuel pressure regulator. I replaced the o2 sensor a few months before I stopped using the car too. I'm not getting any ECM codes when I scan it. I've uploaded 2 videos of what it does:
YouTube - 91 grand prix rough idle 2
YouTube - 91 grand prix rough idle 1
I hope some of you guys could give me some idea on what to check next.
Thanks!