Hi I have a 96 lexus es 300 and it idle normal before I changed the timing belt but when I changed the timing belt now it's idleling at 1500 rpm cold and when the car warms up the marks are dot to dot.I don't know why it started doing that it was fine before this.
If you're off timing I would expect to see an engine light. Any codes stored? If not, possibly you cracked a vacuum line in the process of putting in the timing belt causing it to suck air and make it idle high. Check the entire area where you were for something like this.