[alfa] Re: Motronic Spider failed emissions

[C2slayman@xxxxxxx]

Simon,
       Run a compression test.  A burned exhaust valve would explain the high 
HC - but I'm not sure about the NOx and CO.  Those could be high because the 
cat con is not working effectively(especially if you're dumping raw fuel into 
it from a burned valve).  If compression is OK, then I would find a garage 
that has a pyrometer and have them check the cat con temperature to make sure 
it's working.
       By the way, in the future, it is always better to check the voltage 
output of the O2 sensor before replacing.  I suspect a lot of perfectly good O2 
sensors are sent to the trash bin because of another part on the engine not 
working.  Replacing plugs and filters is probably a good idea anyway.

Cheers,
Charlie

> Date: Tue, 30 Sep 2003 12:56:23 -0400
> From: Simon Body <body@domain.elided>
> Subject: [alfa] Motronic Spider failed emissions
> 
> Greetings
> 
> My 1991 Spider with Motronic fuel injection failed its emissions testing 
> for the second time yesterday.
> Both times it has had:
>   Hydrocarbons ~4x the limit
>   NOx ~3x the limit
>   CO ~25% over the limit.
> Between the two tests, the O2 sensor, filter and plugs were replaced and a 
> bottle of fuel injector cleaner run through it  It was a hot engine with >
> 20 minutes of good running before the tests. There was no improvement after 
> replacing the stuff, in fact everything got about 30% worse !!   I 
> interpret the results as the system running rich, but what can be done 
> about it?
> Help.
> 
> Simon
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