re: Spider NC emissions test results...

[Joe Elliott <jee@domain.elided>]

I've got two suggestions, one potentially dumb and one potentially dumber:

Have you tried introducing a controlled vacuum leak to lean out the 
mixture slightly?

Have you tried sticking copper oxide wool up the tailpipe to convert 
CO to carbon dioxide?

Now back to studying (fluid dynamics exam tomorrow), already in progress...
Joe Elliott
'82 GTV6

At 5:33 AM +0000 2/3/03, alfa-digest wrote:

> Date: Mon, 03 Feb 2003 02:53:34 +0000
> From: JeffreyOlson@domain.elided
> Subject: O2 sensor (w/parts # and price!) and Spider NC emissions 
> test results...
>
> A single-wire (non-heated) BOSCH O2 sensor is available at AutoZone for around
> $18!  Bosch part # is 0258001038.  It will cross-reference to a 
> Bosch universal
> O2 sensor.  Just bought one for my '84 Spider and I believe the same unit is
> used for the GTV-6.
>
> By the way, here's MY emissions saga:
>
> '84 Spider w/good compression but a high-mileage head that lets a little oil
> past the valve seals when coasting down from high rpm's with closed throttle.
>
> NO catalytic converter!  I have a Shankle header and test-pipe and have been
> trying to sneak the car through a NC emissions test.
>
> NC emission limits are 220 ppm HC and 1.2% CO for '84 model year.  I can set
> the idle CO at 0.6% (stock specs) but get a high HC (around 400+ppm) 
> or get the
> HC below 220ppm but end up with 2-3+% CO.  All this with the idle at 
> 950 rpm (+
> or - 50 rpm, stock specs).
>
> Test involves a short 2,500 rpm conditioning run-up and then emissions tested
> at idle.
>
> I have fresh oil, new plugs, new filters, and drive the shit out of the car
> before testing but still can't 'tweek' the idle CO and idle rpm to get the car
> to pass.  The high HC is most likely the result of excessive oil consumption
> and the lack of a catalytic converter rather than a 'rich' mixture.
>
> No vacuum leaks or leaking cold start injector or anything else obvious to
> cause these readings.
>
> I changed the O2 sensor and it had NO effect on emissions, mileage, or how the
> car runs.  The dead O2 sensor (I tested it at temperature with a 
> digital multi-
> meter) was not sending a signal to the ECU so it was in 'open' mode which is
> slightly rich.
>
> The new O2 sensor IS sending a signal to the ECU (within specs) but 
> there is NO
> change in the idle RPM or emissions whether it is connected or not.  Glad I
> only paid $18 for the new O2 sensor!
>
> Next try is 'Motor Restore' oil treatment and 'Guaranteed to Pass' fuel
> additive!  After that I'll break down and buy one of AR Ricambi's or Caribou's
> catalytic converters.  Fortunately with the header set-up I have, it will bolt
> in place where I now have a 'test-pipe' just like on the later Spica-injected
> cars and at much less cost that the OEM one-piece used on the later Bosch F.I.
> cars.
>
> By the way, the Shankle header really perked up the Bosch F.I. 
> Spider!  The 4-2-
> 1 stock exhaust manifold/converter is obviously VERY restrictive!  Car now
> ZINGS right to the redline in the lower gears!  Bit noiser than stock with
> a 'tinny' exhaust note but a noticeable improvement in performance.
>
> Jeff
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