'98 erratic high/low idle with A/C on. 2.5L
Everytime the A/C is turned on the idle shoots up to about 3k RPM and back to a low shaky idle. Thing is, it only does this when the AC compressor cycles back and forth. BTW, the compressor cycles on/off every 4 seconds or so, more often than I've ever seen in an auto. Anyway, when the throttle is blipped it shoots back up high for a few seconds till it eventually comes back down. This causes erratic throttle responses too and affects driving. The only thing that stops this is diconnecting the engine temp sensor which then turns off the compressor. I changed the sensor to no avail. And I did change the correct temp sensor. No check engine light is on. Thanks.