Chrysler Repair: 95 chrysler Concorde went nuts leaving me stranded on the highway, mercury grand marquis, chrysler concorde

Question
I have a 95 Chrysler Concorde 3.5l V6 247,000 miles. the transmission was replaced in 2002. The engine doesnt burn a drop of oil and runs really strong. Stronger then the engine in my 95 Mercury Grand Marquis 4.6l V8.   I was coming home from a court date when i turned off the highway to continue my normal route while acceleration the car developed a slight missfire. which i thought was normal and seems to be. it usually clears up after a few minute which it did.  about 10 miles down the road i realized the tack was jumping from about 2,300rpm which is normal for 65mph to about about 5,500 and down to nearly 500rpm at points. with no sings of tranny slippage or change in engine noise. I didnt like this so i dropped the car in neutral and began to pull on to the shoulder when the engine just died. I turned the key off after stopping and attempted to restart the engine. It started right up like nothing was ever wrong. I continued to drive as i thought what ever it was had been corrected. Until. it did it 3 time in about 10 miles. I thought maybe the trans was slipping. so i started it back up. put it in and drive and flat out floored the mother, it lit up the tires clear through 1st and second gear. it drove fine for about another 3 miles when it did it again.  It fired right up. i Opened the hood to check if anything was out of the ordinary. I do alot of work to my cars my self so i know somethings.   While looking under the hood the engine began reving on its own. from idle to about 2,000rpm and back again. at points i would step on the throttle to maybe clear it up. and at some points the throttle didnt respond. after a few minutes of this it corrected itself. I new i had to get it home before it finally quit. something wasnt right. i would check on it at home more completly.  I began driving it again, a few minutes later it did the same thing, this time not starting back up.  while it would do its reving thing the engine light would come on when the revs climbed past normal (2,300rpm) the cruise light would also come on and off with the engine light.          Im not 100% sure but while it was doing its parked revving thing i beleive the throttles were not opening.

Answer
Hi Josh,
Try for a fault code readout using the ignition key:"on-off-on-off-on and leave on", doing that in 5 seconds or less elapsed time. Then count the flashes of the 'check engine' engine light which will begin. Repeat the flash counts, then let me know the numbers in the order of appearance and we'll go from there.
Roland
PS Sorry for the delay but my computer failed recently.