Inherited 87 park ave. had to jump start to move.
car idles erratic i.e. rpm up N down. either is misfiring or....sounds like bad valve. Starts ok,
drives ok, rides ok. check engine light goes on
after driving and letting foot off gas pedal. stays on until turned off car is turned off. like the car but......Oh yeah, It shudders around 60mph

The best thing to do is go to a shop and have them read the code in the computer. The car is at the age where the computer doesn't give alot of info but it would be a good start.