flunked smog in California

[jamulbill]

I just bought a 79 2000 at auction and in the glove box there was a smog failure notice. It said that the CO levels were too high. I haven't done a tune up or anything yet so before I get it smogged again what should I look for?

[So Cal Mark]

a tune up won't help co levels. First, make sure the choke is opening fully. Next, make sure the air injection system is working. Third, the carb probably has to be rejetted to pass.

[jamulbill]

How do I test the air pump?

[So Cal Mark]

take the hose off the check valve, start the engine and feel for air blowing out the end of the hose

[jamulbill]

OK the old airpump wasn't working so I replaced it, I fixed the choke, I adjusted the timing and it still flunked smog. Would using the colortune let me adjust the mixture so that it would pass? The guy at the emission shop said it was running too rich.

[So Cal Mark]

typically, I have to rejet the carbs quite lean to pass the test. Can you post the readings your car got?

[jamulbill]

The test results were :
idle 831 co2 12.90 , 02 2.8, HC 345(fail) , CO% 0.00
2500 rpm co2 13.74, o2 0, HC 111 , CO% 2.01 (fail)

[So Cal Mark]

it's lean at idle and slightly rich at cruise. You must live in the desert since you got the two-speed idle test. Pity, it's harder to pass those. Check for a vacuum leak at idle. If none found, richen the idle mixture about 1 turn. Don't richen any more than necessary to get peak idle speed. Set the idle speed to 1000rpm, make sure the timing is set back 3 degrees from factory setting. That should cure the idle failure. For the 2500 rpm failure, swap the two air jets in the top of the carb from the primary to secondary. After the test swap them back

[lvacordian]

I also just flunked an emissions test in Ventura County, CA. with very high CO & HC levels on my 1978 124 Spider. The emissions repair tech is suggesting that I start with rejecting the carburetor, overhauling the air injection system starting from the diverter valve down to rail on the block, and static time the ignition and cam timing.

At the time of the test my timing was 44 BTDC. I’ve timed the car many times only being able to get it to run smoothly at the 10 degree mark on the timing belt cover. I do not know why the timing was at 44 BTDC during the time of the test. I’m thinking that maybe because the car was tested at such a high RPM? It’s 0 TDC at 850 RPM right?

Here are my test results:

1843 RPM HC 338 (FAIL) CO 6.93 (FAIL) Co2 10.2 NO 496 O2 0.3
2086 RPM HC 317 (FAIL) CO 7.09 (FAIL) Co2 10.1 NO 498 O2 0.3