Olds cutlass supreme 1992 idling at 3000 rpm. Changed throttle position sensor, cleaned IAC valve, what next? TP sensor made check engine light go off and temperarily idle normally, next morning back to FAST idle.
Block off the throttle-body mouth, if no reaction with rpms, false air getting in there from somewhere. Take the throttle linkage loose, any effect? Take the wiring connector loose from tps, any effect? Any applicable mil codes?