Opinions needed re: engine hesitation/vibrations

[RED IS 91]

Thanks Alpine
I did disconnect the big vacuum line before and the motor immediately died .
I still need to check a bunch of sensors using the bentley manual .
I was wondering if anyone had any experience with the coolant temp sensor.
I've read on numerous threads that  that sensor if faulty leads to rough idle and poor accelleration .I just don't want to start replacing parts ,I'd like to find the problem by analysis ,not by parts changing.
Like anything,work  gets in the way of working on the car .

[RED IS 91]

Update

I changed out the thermostat ( The one I removed said China on it :mad: )
I flushed the cooling system and installed new antifreeze with distilled water.
I changed out the oxygen sensor .
After all this car still ran like it was running rich.
I did another code check and this time I got back mas code .
I removed it and sprayed carb cleaner on it
VOILA ,,the car seems to be running good now but I'm keeping my fingers crossed .
PS  I worked my ass off trying to get that old oxygen sensor out .
torches and everything .
Then I squirted some PB Blaster on it and 15 minutes later it came right off .
I am now a believer in PB Blaster.

[Alpine003]

I am now a believer in PB Blaster.

Glad you found the problem.

All you have to do is spray WD40 into a styrofoam cup and PB Blaster into a separate cup and watch as the PB Blaster eat through the cup. Just like their ad campaign. haha.