1997 Ford Thunderbird Got 97 3 8 After Car Warms Operating Temp Losses Almost

I got a 97 Thunderbird with a 3.8. After the car warms up to operating temp.it losses almost all power .it will barely move while in gear.the manifolds r turning red hot.any ideas? This is what I've done so far.dropped the exhaust from the manifolds n ran it like that.thinkn the converters r plugged.not that.also changed the coolant temp sensor n pcm too .no luck.and it isn't shootn any codes.had it hooked up to the modus scanner watchmen the freeze frame n everything seems to be workmen no missfires or faults.its gettn 40 pounds of fuel pressure.I'm stuck can any one help solve this mistery? Also how can I check the timing without takn it apart.what should the spark advance be at