my 90 seville seems to be idling rough and eating up gas. it doesnt do it all the time but more so then not. just replaced the o2 sensor. and had the converter and all the injectors replaced a year ago.
surging and excessive fuel useage off and on on 1990 Cadillac Seville
You need to have this issue Diagnosed with a scanner. it could be dozens of things. i used to work at a large GM Dealership and this is the best way to go.
TPS problem. There is a procedure to setting one on this car.