intermittent black smoke

[Tony Hoffman]

Definately does not sound like a timing issue. As mentioned, check the
wiring for the O2, and I'd hook up a meter from the O2 sensor and watch it
while driving. Engine grounds are also a good thing to check. Watch what the
O2 sensor does when the problem occurs. Also, check the wiring from the
coolant temp sensor, and the sensor itself. It may be a bit hard to check
for consistancy, though, since your problem is intermittent. This could also
be spark related, but sounds unlikely.

Let us know what you find,
Tony

On Fri, Jul 8, 2011 at 9:07 PM, Jean-François Roldan
<roldan_jf at hotmail.com>wrote:

> Hi all,
>
> For the past 3 days, I have been driving along fine on the highway when all
> of a sudden, the engine loses power a bit, hesitates, and clouds of black
> smoke are clearly visible... the back of my car is now all dark from it.
> Then it goes away like it came, power comes back, pedal response too...
>
> And a few minutes later or 20 minutes later it starts again... power drops
> but speed stays around 50-55 mph. When it is smoking like that, if I try to
> accelerate, there is no throttle response, just more smoke... until all goes
> away and it is back to almost normal...
>
> any ideas? could it be timing related? TB was done almost exactly 60K ago
>
> JF
> 91 200 tqa, 210K