Re: meaning of emissions test report

[Don Hoefer <hoefer@eng.pko.dec.com>]

Sam Nicholls wrote:
> 
> My '86 4000S (1.8 litre) passed the Texas state inspection emissions
> test!!!  This was the first time it's had the test and I was a little
> concerned.  Anyway...
> 
> Can anyone tell me if these numbers look OK?  I'm concerned about the
> HC test.  My score seems a little close to the limit.  Also, what is
> the 'Dilution' test?
> 
>                     EMISSIONS TEST
>                        STANDARD    TEST    RESULT
> ------------------------------------------------------------
> CO (%)                    1.20    0.08    PASS
> HC (PPM)                   220     192    PASS
> DILUTION (CO+CO2) (%)      6.0    15.1    VALID
> RPM                       1600     907    VALID
> 

The HC numbers do look high.  They should be way below 100.
Was the car warm?  The oil temp should be >= 80C.  Hydro-
carbons can build up in the exhaust system.  I run my car
at 70MPH in third gear for a mile or two before the test
and then I don't shut the car off until after the test.
Beyond that look for HC sources, like oil consumption, etc.

Don Hoefer
'82 Coupe