1991 Buick Century 91 Buick Century 3.3

Hi :-)

I have been having issues with this vehicle for a while now. Idles ok, and runs ok when cold, once engine gets warmed up. there is a shaking on deceleration at about 35 mph. Had one coil go bad and replaced all three, also replaced fuel filter and icm. car runs better but, has shaking on deccel, and acts like it wants to stall at idle.
Any suggestions would be helpful as I am ready to rip my hair out at this point. lol

thanks in advance :-)
sandi