89 420 sel 02 snesor
 

I have an bad idleing problem I can't figure so I'm nickel and dimeing it.

I replace the fuel filter, still rough idle

I replaced all spark plugs, still idle rough

could 02 sensor cause rough idle?

Thanks

could be injectors, temp sensors, vacuum leaks, spark plugs, wires, distributor cap and rotor, fuel distributor, etc etc etc. This problem could nickel and dime you to the poor house. Id do a search on it and see what other people have come up with...

Please add a better description of 'bad idling'. There are far too many variables. Words like too low, speed goes up and down from xx rpm to yy rpm, black smoke, hissing noise etc etc etc.

It started suddenly
 

The 89 420 SEL runs fine above 5mph.

Starts great, idles rough, give it gas and most time it goes just fine, but here latly it has started hessitating when you give it gas.
Last week my wife was driving and was stopped at a green light ready to turn left, as an opening came up in the traffic she gave it the gas to go and it started spitting and sputtering as it rolled into the oncoming traffic. As the car stalled, but never cut off, she had the entire two left of on coming traffic stopped as she tried to make it across the interection. She lost her green light and the traffic started rolling up to her side window because she was blocking their ability to go as the car sputtered along at 1mph. Finally at about 30 seconds later and after she stopped all traffin at the red light, the engine smoothed out and took off running fine again,
You never know when it's going to fail.
Usually right after starting it sputters for about 20 seconds. You can press on the accelerator but it just sputters, after 20 seconds it will take off and run great at 5mph-80 mph.

Retired and poorer now thanks to Obama, I can't spend alot of money, but I can spend my pension check on little parts until Obama takes that away too.

Help

An hour of diagnostic time at your local indy shop would serve you very well and probably save you money in the long run.

If it were my car, I'd check idle air control, fuel pump output volume & pressure, and all my of grounds & electrical connections.