Re: New California smog for older Volvo
> Been there, done that. My last test was February. It passed after some
> creative plumbing re the ICU. It's always been borderline, usually
> within a point or two of max on NoX.
> Many smog stations will do a pre-test for a nominal fee.
> My '83 245 has been through several tests in the 9 years I've owned it.
> First mistake was *not* getting a pre-test. It scored a GP (gross
> polluter) which now forces me to go to a test only station.
> The pre-test guy may not be thorough (the test only place will be hard
> core) so some key points to watch for:
> Be sure they check the gas cap (or buy a new one.) I had a perfectly
> good passing score fail (and they charge you anyway, btw) because of a
> leaky cap.
> Be sure the vacuum lines and heat riser hoses are connected and in good
> shape. (I got nicked once because the heat riser hose had slipped off.
> Nope, they don't let you put it on, they fail you and take your money...
> thank you, come again.)
> Once, after a passing pre-test, drove 5 minutes to the test only place.
> The test only guy noticed the vacuum line to the (Ignition Control
> Unit?) was off. Of course it will pass with that unplugged. He hooked it
> up (apparently they are allowed to reattach vacuum lines... wtf?) and
> the motor pings to beat heck... and fails.
> Be sure it passes pre-test with reasonable margins. If you're within
> .02% of max on NoX, you can bet it will fail the real test. (no, all the
> machines are not calibrated exactly the same.)
Further to the bottom part of this post, talking about the vacuum line
to the ignition control unit...
That vacuum line advances the timing at part load a lot, in an attempt
to improve fuel economy. This way the engine is always running at the
ragged edge of ping, which is great for NOx formation (i.e., not good).
Disconnecting this hose will not harm fuel economy enough to be
noticeable, but will reduce ping and NOx formation. Ironically, smog
centers don't like you to do this, even though it reduces emissions! I
put a ball bearing into the end of the hose before pushing it back onto
the vacuum advance on the ignition control unit, so it doesn't look like
anything needs to be reconnected - just make sure the ball fits tightly,
if vacuum gets in there and can't get out, then your timing will be so
far advanced it won't run well. The hose goes under the engine by the
crankshaft pulley, so there's lots of ways to inventively block this
Thornhill (near Toronto), Ont.
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)