Im kind of guessing at idle from the tach on dash, its not too accurate. I could put a real tach on it, but it is what it is anyway, the ECU controls it.

No, I havent replaced plug wires...yet. That wouldnt make the idiot lights come on, so there is still something else going on, even if its not responsible for the rpm fluctuations under acceleration. I did regap the plugs when this started at the same time I changed the fuel filter.


Might be a good time to bring this up. Spark has seemed weak for a long time. Occasionally over the last few yrs (once a yr or so) it would develop a rough idle and rough running under acceleration. In those cases there was usually a cylinder that noticeably wasnt contributing its fair share. Simply returning plug gaps to spec would clear it up. I know when it was much newer that didnt happen. But it never dropped rpms and then picked them back up the way it does now.

Once, I even developed a bad spark plug. I could swap it between cylinders and the miss would move with it. Never had that before in my life, but it happened. Changed out one plug and it ran great again.

Maybe the oil in the plug tubes had something to do with that stuff.