RPM jumps when releasing gas pedal/ cruise control

[jgru]

Hey everybody!


I have a 2001 Grand Prix SE with a 3100 in it. The car has 135k miles on it. For the last 10k miles or so the rmps have started to jump when either the gas pedal is released or the cruise control is disengaged. It is much more drastic when the cruise control is disengaged. Usually the RPMS rapidly jump somewhere between 200-1000 rpms in a split second before going back down to what they should be at. This is happens much less drastically when releasing the gas pedal, but still happens. On top of this the car has other problems including a knock and a pressure control solenoid that is malfunctioning in the transmission. I was wondering if anyone had any ideas to what could be causing the problem


Thanks for any input!

[djudge1970]

When my cruise quit working it would gain speed and not turn off. Could be unit or have you checked for any vacuum leaks?

[Fivefingerdeathpunch]

Perhaps the trans codes are making the torque converter unlock more prominent.

Because when you do let off the gas at cruising speeds, the torque converter will unlock and the rpm should rise slightly and then fall back down as the rpms and vehicle speed get reduced.