Chrysler Repair: 2.5L V-6 intermittent spark, crank pulley, pulley bolt

Question

Hi,I am another lost Chrysler cirrus 2.5 liter owner.i had the stall,and no start problems all last summer,after changing distributor,O2 sensor,crank censor,car ran great.Wallet was very thin,but what a relief to have our car back.Parked car at seven o'clock PM,tried to go to work next morning at six NO START AGAIN!!!CAR NOW HAS BEEN SITTING FOR 2 MONTHS,STILL NO START,CHECKED ALL ITEMS HAVE GREAT FUEL PRESSURE BUT INTERMITTENT SPARK!I have been told that the problem is my ECM,but before dishing out another 500 bucks,i was wondering if this seems right or if this is a common problem.Car has 190000 on it but is rust free shiny and a pleasure to drive.we have serviced this vehicle every 3000 miles and other than this mystery problem of late has been a great.PLEASE HELP US.also where is the ECM located?

Answer
Hi Brian,
I wonder if intermittent spark would be due to either the cam (distributor) or crank sensor, or possibly simply the distributor rotor or its cap. The cap has a built-in 5,000 ohm resistor between the center button and the spark coil contact. So the rotor should show continuity. Have you actually checked for spark with a spare spark plug inserted in one of the plug wire caps and held the threads against the block to observe the spark consistency? What do you mean by intermittent?
Also, you can check check the voltage output of the two sensors, measuring between the two wires (tan/yellow, black/light blue on pins 3 and 2 at the distributor) and at the crank sensor (gray/black, black/light blue) using fine pins to pierce thru the insulation. You would turn the crankshaft by hand using a socket on the crank pulley bolt and with the ignition in the 'run' positon. The voltage should oscillate several times per revolution between 5 and 0.3V if the sensors are good.
Of course a readout with a code reader would be good to do. I don't think the ignition key will give you a code readout on the odometer window of a '98 but give it a try: on-off-on-off-on and leave on, doing that in 5 seconds or less elapsed time. If that doesn't work then try to borrow a code reader and plug it into the socket under the dash by the steering column.
I hope you will find the cause of the spark issue.
Roland