Failed emissions due to timing? Can it be?

[Dave Haupt]

THere's nothing wrong with the timing.  I read further
in the Bentley - the 15 degree spec is for the
non-turbo engine.  The actual spec on the MC and 3B is
TDC, but it is not measured with engine running.  The
adjustment is static, done by setting the flywheel and
camshaft pulley to TDC, then rotating the distributor
housing to align two marks.  I checked mine and it's
fine.  

As it turns out, if the underhood emissions sticker
does not indicate a timing spec, then the technician
is supposed to waive that part of the test.  In my
case, I got a shade tree mechanic who assumed that if
there were spark plugs, then a timing light was
needed.

The state recommended I find a more experienced smog
test place, and interview them to make sure they
understood this.  

"It's a 200, not a 100.  Don't follow the timing
instructions for the 100, because it's not the same
enigne.  Read the sticker."  

Dave


--- Dan Cordon <cord4530 at uidaho.edu> wrote:
> > Subject vehicle is a 1989 200 turbo quattro sedan,
> > early MC engine with single knock sensor.
> > 
> > The youngster at the smog station claimed "the
> timing
> > measures 10 degrees BTDC and it should be 15
> degrees".
> >  The Bentley confirms it should be 15 degrees,
> however
> > it also claims it's not adjustable.
> 
> <snip>
> 
> I haven't experienced this first hand, but isn't it
> pretty common for 
> the front pulley to slip out of alignment? I thought
> I've heard many 
> people doing TB jobs and found the TDC reference had
> moved notably. It 
> could be that yours has slipped 5°. Just a thought
> anyway.
> 
> While improper timing can certainly give poorer
> emissions, you didn't 
> mention if your car passed (or was tested yet).
> Could be your timing is 
> fine with the pulley slipped, or it could be the
> ignition is being 
> retarted by the ECU too. Perhaps it's falsely
> detecting knock?
> 
> -- 
> Dan Cordon
> Mechanical Engineer - Engine Research Facility
> University of Idaho
> 


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