I have a 95 Mustang GT 5.O SN95 that has been random surging RPM's for months. It happens about 20 minutes after I start driving on the highway or streets. The car don't move any faster but will jerk if I'm on the highway & the RPM surges. It surges anywhere from 1000 to 2000 above normal. I changed cracked vacuum lines, cleaned the MAS & throttle body 5 times, lubed the springs & cables on the throttle body & cleaned and tested the iac, none fixed it. I tested the TPS, it wouldn't go below 1.09 volts throttle closed and 4.85 wot. I bought a new TPS & it reads 1.38 volts throttle closed. Car has more power & responded better but RPM's surged but not as high or as much. The TPS is non adjustable, any help would be much appreciated.
Never mind just noticed you said it does it while driving on the highway. Iac wouldn’t do anything at highway speeds. Sent from my iPhone using Tapatalk
