1987 Oldsmobile Ciera

Engine Performance problem
1987 Oldsmobile Ciera 6 cyl Two Wheel Drive Automatic

the engine cuts out when I let off the gas. What could this be? Is the fuel pump not working? How can I check it?

If the fuel pump was bad, chances are it would die when you press the gas. Have you checked for vacuum leaks? Does the car start right back up? Has the check engine light come on?

No it does not cut out when I back up or press the gas. I cant find any leaks. And yes the check engine soon light is on

I changed my spark plugs and it ran good for a while. Then it started running bad again. But when I do the spark plugs again it will run good again. For a little while atleast. What could this be. Could it be the coil packs? Or the coils computer

If the light is on, have the computer scanned for codes. Most parts stores will do it for free. As far as the plugs, when you remove them, are they black?

I got the coders off my car. The first one is rich exhaust indicated ( left side on dual oxygen modules) the second was electronic spark timing (EST) circuit- low voltage detected. Electronic spark control (ESC) Circuit problems. What do I do to fix these probablems?