Chrysler Repair: engine or transmission?, driveability problem, liter engine

Question
i have a 1995 intrepid with a 3.3 liter engine and a recently rebuilt transmission. sometimes the idle in the car fluctuates between 400 rpm and about 700 rpm according to the tach. and sometimes at idle it will stumble to almost stall and then pick right back up again. sometimes when driving it feels like it kicks out of gear and then right back in again. most times it runs good but this happens every couple of days. i took the car back to the transmission shop and they drove it and scanned it and everything in the transmission checks out fine. could you possibly please help me to figure this one out?

thank you so much for any possibilities.

          SCOTT MCLEAN

Answer
Hi Scott,
A "driveability" problem should begin with a readout of the engine controller fault codes, which is separate from that of the transmission controller readout. Just take the ignition key and switch on-off-on-off-on and leave on (where 'on' means the run position) within a period of 5 seconds elapsed time. Then watch the check engine light to begin to flash, pause, flash, pause, etc. Count the number of flashes between each pause. The last two groups will be 5 flashes each. Write down the numbers as they come out or make a mental note of them. Then write back with the results and we'll go from there. You can repeat the readout as often as you like to assure an accurate assessment.
Roland