thanks for the reply, guess its time to get the car back on the road! btw, i have checked the piston in the distributor, its ok. i have not checked the oxy sensor until just now. i moved the car around to my shop after not starting it for a long while. started and ran good, no chugging. turned it off after 2 minutes, raised it up, grabbed the o2 sensor and unplugged it. started the car, it ran good for 1 minute or so, then rpm slowed to about 500, started chugging but did not die. ran like this for 5 minutes. raced it up a couple of times but it returned to steady 500 rpm but black smoke rich. temp by this time is almost 80c. turned off, plugged o2 back in, started car, ran as before but got worse steadily until car died within 30 seconds.
thanks again, mark