Hello. I have a 2000 Buick Regal LS (6-cylinder) and it has developed a
real bad problem of not starting properly and when it does start, it
keeps cutting off. The strange thing is though is that it doesn't
happen everyday. It's very intermittent. I can go one or two days and
it will run fine, driving it to work and everything. But the next day,
it'll act like it barely wants to turn over and sounds like it's
flooded. During this time, the car emits a real dark, grayish smoke
(not white like an oil problem). If I give it a lot of gas for like 5-7
minutes, sometimes the engine will return back to normal. Other times,
no success. Then, I'll park the car for about 3 days, go back to it
and it works fine.

I'm already in the hole $1000.00 after taking it to four different
places. I've had a fuel pump/fuel filter put in; a mass air flow
sensor replaced; had two diagnostics performed and oil cleaned out of
the box where the mapping sensor is located because I was told that
could be giving the computer false readings. On my most recent car shop
visit, the mechanic recommended that I have the spark plugs/wires
changed but he couldn't guarantee that would fix the cutting off
problem. Oh yeah, if I do get the Regal to run normally, it might cut
off on me while waiting at a stop sign or stoplight or even while
driving! It did so while going about 45 and 25 mph respectively. I was
also told that I may have an intermittent ignition control module
problem or a faulty catalytic converter. Yikes! Plus, the o2 sensor is
showing rich all the time. Could I have an electric short somewhere?
How do you check for that anyway? Current mileage on the Regal:
126,000+. Any thoughts on how I should proceed would be greatly
appreciated. Thanks.