Surging 3.3 at idle or when slowing

Having another problem with my 1993 Grand Voyager with a 3.3. No fault
codes other than a 12.

Sometimes while waiting at a signal, the idle speed will increase for
a second or two, causing the vehicle to lunge forward to the
unsuspecting driver.

It has also done this when slowing down too.

It does it with the A/C on or off, so I don't believe that it is the
idle speed being adjusted to compensate for the A/C compressor coming
on.

02 sensor was replaced, along with the throttle body being cleaned
3000 miles ago.

Any ideas welcome. After having had the transmission rebuilt last
week, I don't want any other expensive repairs.

Thanks,

KM

 

A scan tool to see what the sensor values are at the time it happens, could
be a MAP or TPS voltage problem or anything else for that matter

Glenn Beasley
Chrysler Tech

 

I don't have a scan tool, but will be taking it to place that does. I
will have them start with those two things.

Thanks,

KM

 

Code 12 ... Hmmm... Check threads "Car stalling/surging" and "Door locking up without cause" Jacek