Failed Smogging...

[dgranet]

I failed the California smog test on my 92 SVX but only at low rpm (550). At high rpm did great.

Don't want to spend the $$ on new catalytic converters if I don't have to. Can I just speed up the slow idle?? If so how?? What about fuel mix??

Thanks!!
David
92 svx
75K miles..

[Beav]

What exactly failed? I/we need some numbers to work with here. How long since air filter and spark plugs? Have you cleaned the MAF? Any other details helpful.

[dgranet]

OK here is the info-

My HC was measured at 195 (average is 29 with a high of 120 at an rpm
of 595.
At an rpm of 2669 my HC was measured at 9 (20 avg, 140 max).

My CO (5) was 1.38 at an rpm of 595 (avg 0.10 max 1.00).
At an rpm of 2669 my CO was 0.00 (avg 0.10 max 1.00).

So it was at the slower idle speed that I failed.* Does that ring any
bells?* Is there a way to help the car pass without repair??* Are there
simpler fixes??* It still drives great.

Thanks!!

David

[dgranet]

Oh the air filter is clean and oil just changed. Anything else??
David

[Beav]

HC is unburnt fuel, CO is poorly burnt fuel. The low numbers at hi speed indicate that the cats are doing their job. I'm trusting that you had driven the car for at least fifteen miutes before the inspection, it has to be fully warmed-up to pass. Your numbers aren't really that bad, it looks to be a small misfire or a dribbling injector.

If the spark plugs haven't been changed in a while that's where I would start. Look at the ones you take out for any signs of misfiring or oil contamination (or just look for any that are different from the rest.) Also listen while the engine is idling for vacuum leaks, look around for split hoses, etc. and that the large tube from the air filter is secure at both ends.

[dgranet]

Thanks !! Will do.
David