Shop Having Trouble Getting My Car to Pass CA Smog

ikarcuaso · 10-09-2008, 01:33 PM

Yesterday, I brought my SC to a shop (local 911/German place, PCA member, familiar to some board members etc.) to have the the air/fuel tweaked, perform a smog pre-test, and brought nearby to a test-only place. It failed yesterday P.M. (high CO), so they kept it overnight, said they didn't want to go back to the test-only place 5-10 min. later, might not look right.

Anyway, I just called the shop, and they said they're still having problems getting it to pass, still to rich. They said they adj the timing, air/fuel, etc.

I passed two years ago after a top end rebuild. O2 sensor is fairly new, etc. Nothing significant has been done to the car since. I'm troubled by their inability to get it done. Any thoughts?

As of now, I'm planning to p/u the car this afternoon, pass or not. This sucks.

jrumiano · jrumiano's Garage

Have you looked at your cat converter? I have an 85 911 coupe that would not pass inspection. I finally took the cat off to have a look. It was totally melted down inside. the car ran fine (somehow) even thought it was melted down. I had high CO also. After replacing it, the car passed with flying colors. BTW initially my mechanic didn't think it was the cat...

Good luck,
John

ikarcuaso · 10-09-2008, 02:57 PM

Thanks for the suggestion. I guess it's possible the cat could have gone bad over a couple of years.

I haven't spoken w/the shop yet, so I haven't heard their latest explanation. If it hasn't passed yet, I'm going to ask how much $$ if they kept trying, but I'm leaning to just taking my car.

Schwarzeritter · 10-09-2008, 03:13 PM

Make sure that they warm the car fully, I have seen alot of 911's early, middle, late, even alot of the mid 90's BNW's more so the five series start failing.

Tell them too warm the car up for at least 30min, inspect if the Smog tech is just smashing the throttle or if they are depressing the throttle smoothly. As I have seen a good many cars
not just 80's Porsches, but RX7's, Supra's, BMW's all of which were 90's fail.

ikarcuaso · 10-09-2008, 03:27 PM

Thanks. I'm just assuming the shop owner understands not to smog a cold engine. He's no 911 novice, but no, I didn't explicitly ask him this. I just assumed it's SOP.

Still no word...

hifeverz · 10-09-2008, 04:01 PM

I too failed a smog check test due to high CO. My CO at failure = @15mph (1.94%), @ 25mph(1.90%). Upon New Smog Pump replacement it passed @15mph (1.26%), @ 25mph(0.76%). On a previous thread I commented as quoted below.
Hope this helps!
Hz

09oct08

SMOG Failure in California

I have a 1979 911SC (265k miles on car and 160k miles on the 3.0 liter engine) that failed smog about a month ago. I had changed out NEW the spark plugs, ignition wires, rotor, cap, air filter, smog pump air filter. I had the valves adjusted, reset timing and put in a good used smog pump . . . AND I FAILED !! . . . too rich was the results. I was thinking it may need a new cat, since it was 1979 vintage original!!?? The tech indicated to me that everything seemed fine and that he thought that my smog pump was NOT pumping enough air to dilute the exhaust gases. I therefore had a rebuilt pump already at hand to install. I got retested and it passed with flying colors.
Whew . . . good for another 2 years! . . . and imagine I have one broken head stud that I still should fix . . . !!

Good luck,
Hz
28sep08

ikarcuaso · 10-10-2008, 05:41 PM

For everyone keeping score at home

I PASSED!

I failed before 'cuz CO was too high @ 25 MPH. Glad to get this crap behind me.

DasBoot · 10-10-2008, 05:54 PM

Quote:

Originally Posted by ikarcuaso

For everyone keeping score at home

I PASSED!

I failed before 'cuz CO was too high @ 25 MPH. Glad to get this crap behind me.

Do you know what the cause of the initial failure was? Remedy?

ikarcuaso · 06:07 PM

The air/fuel mixture was set too rich, for smog testing, anyway. It just had to be leaned out, and they adjusted the timing, as well. If I had more time and a gas analyzer, I would have done it myself. I've used a volt meter in the past, but I don't think it's all that precise.

After the test, the shop adjusted the car back to more "suitable" settings.

Paulporsche · 10-10-2008, 07:00 PM

Try to get the setting figures from them, or at least how much of a turn was reqd to go from "pass" to "suitable" for next time.