1984 280SL Smog Test Results

[ctaylor738]

Today I took my newest problem child in for its smog restest. Car has 160K on it and smoked profusely. Following a head rebuild, I had it tested for emssions and it failed miserably.

So, did the following:

- Installed an 87 degree thermostat
- Installed a Timevalve cat and header pipes with a fitting for an O2 sensor
- Cleaned injectors
- Installed a Bosch single wire O2 sensor ($16.95) pre-cat. Ajdusted mixture to get close to the reference voltage of .45v, which according to the is the ideal 14.7 air/fuel ratio. Car runs very well.

The results of the test surprised me. Idle and 2500 RPM were very similar:

HC ppm: 26 Limit: 220

CO%: 0.00 Limit 1.20%

Basically near new car standards.

Who says these old hooters are polluters?

I live here in smog free California. Received the
dmv renewal. Older cars require going to a smog only
station that examines the car in more detail. As always I
was worried about my car. Brought it to regular mechanic
who made some adjustments and then took it over for the test.

Car passed. Only downside is that the inspection now coat $80 to $100.

Im now legal for two years. My car has been trouble free for past seven years and 36,000 miles driven

steve. '84 280sl 5 speed. 183,999.5 miles.

[Carrie_Bacon]

Hi guys!
My husband took our '84 Euro 280sl in for smog testing a few weeks ago - we were concerned as no converters (as far as I know) were installed on the car... We purchased it last year from a man in VA and it had passed there. Our car passed, here in Connecticut, with the following results:

HC: 166 PPM (limit 167 PPM)
CO% 0.53 (limit 0.53%)
NOx: 406 PPM (limit 1167 PPM)

[deanyel]

Originally Posted by Carrie_Bacon

Hi guys!
My husband took our '84 Euro 280sl in for smog testing a few weeks ago - we were concerned as no converters (as far as I know) were installed on the car... We purchased it last year from a man in VA and it had passed there. Our car passed, here in Connecticut, with the following results:

HC: 166 PPM (limit 167 PPM)
CO% 0.53 (limit 0.53%)
NOx: 406 PPM (limit 1167 PPM)

You need to get those NOx's up closer to the limit.

[Carrie_Bacon]

Dean,
Duh?! I mean, I know the car needs a tuneup... But that will have to wait until after I get the "new" (listed on my signature line) 500sl home, in a week or so... Good to hear what works and doesn't work for cleaning up emissions...
Carrie

[ctaylor738]

If you are at .50% CO w/o a cat, you can richen it up a bit and get a nice boost in power and drivability. Your HC indcates it's time for an ignition tune-up and maybe some better injectors.

I am surprised you passed a smog test with no cat - in VA with a 1978 or later car, you flunk without one, regardless of the readings.