O.K.!!, thanks for all the replies. The problem is gone after replacing both coil packs and the ignition module, nothing that $4.5K could not fix and the monster is back. Now a new problem!!! the driver door becomes paralyzed, nothing works, even the automatic door closer. All the buttons are dead, no power at all, but intermediately after a while the power comes back on and usually stays on, until the car is turned off. I checked the plugs under the seat and there is constant 12 volts whether the ignition is on or not, so I'm thinking maybe the a connector or a relay is not working properly?

 

check the wires in the "accordion" between the door & the body when the door is open. they short out and/or break- this is a very common problem. do a quick search- there's lots of posts on this issue.