Recently my 89TS has been staying at a high idle.1200 +/- and occasionally it seems to be searching for idle once it is warmed up. It jumps back and forth 800/1200 rpm then will eventually settle back at 1200 which I know is too high. I suspect there must be a sensor to know it has come to temp and should drop the idle and I am suspecting this is also the cause of the idle searching ? Temp is about 195 and fans do come on. Thanks in advance.