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-   -   I failed smog :( (http://forums.pelicanparts.com/porsche-911-technical-forum/238945-i-failed-smog.html)

Steve87-911 09-01-2005 03:01 PM

I failed smog :(
 
Here's my readout. I had gotten the motor real hot prior to the test and the cat is only a 1 1/2 yrs old.

I suspected I'd fail because the tech left the engine idling for too long before testing. By then it started smoking as he did the idle test. I suspect bad valve guides since it uses lots of oil. (This car passed fine last year tho...I wonder how.) Would these readings be consistent with burning oil?
http://forums.pelicanparts.com/uploa...1125611798.jpg

I'll call a p-car wrench to see what I can do but would appreciate your advice. Since I'm moving Seattle area later this month I guess I'll just wait until I get there and have a Seattle area p-car expert test it out and make recommendations.
Dag nabit!

Joe Bob 09-01-2005 04:45 PM

Run a load of Techron thru it....load up with 87 octane.

Pre test it. See if you can adjust mixture....my 3.0 CIS I could...can't on my 3.6...dunno if the 3.2 can be....

If it still fails, disconnect one of the injectors....instant air pump....

Oh yeah...take it to the guy on Chapala at the Brake and Muffler shop next to the Shell station...has an English accent, tell him I sent ya.

dvkk 09-01-2005 11:39 PM

O2 sensor?

It is running rich. Your O2 sensor could be bad. Is it hooked up?

Wayne 962 09-02-2005 12:49 AM

Yes, running way too rich. You are failing smog and leaving power on the table by not fixing this. Check the O2 sensor...

-Wayne

Steve87-911 09-02-2005 08:04 AM

Would burning oil also make it look like I'm running rich?

When it started smoking after it idled so long it looked like gray smoke...not the blue oil smoke and I didn't smell oil burning. (I thought black smoke indicated richness.)

I hope you are all correct. Fixing the O2 sensor and maybe adjusting the mixture would be a heck of a lot cheaper than tearing down the top end.

Thanks so much!

stlrj 09-02-2005 08:20 AM

Running too rich will cause your engine to burn oil and wear out your valve guides too.

Joe

Steve87-911 09-02-2005 08:20 AM

Hold the phone! I just checked and the O2 sensor was disconnected! I plugged it back in and am going to take her for a cruise and see the diff and have it pre-tested and then smogged again. Guess I need to call the dude who R&Rd my engine last year for a new clutch.

Steve87-911 09-02-2005 09:27 AM

So I hooked up the O2 sensor and took her for a 35 min drive...got it nice and warm.
Came home at let it idle for 3 or so minutes (like at the smog station) and no smoke! After idling that long if I then rev it up I get a couple puffs and it clears right up. So next week I'll go to the smog station again. Crossing fingers.

ficke 09-02-2005 09:52 AM

First congrats. on the O2 sensor find. Just for the record, burning oil does not effect what is being tested you can have a smoking junk heap that can pass and a clean looking exhaust that fails, Remember they our testing for CO which is a tasteless, colorless, orderless, deadly poisons gas and HC which is raw gasoline the stuff you smell when you have an open container of gasoline, the fumes. Diesels with all that ugly smoke they produce do not make CO, that is why Diesels can be used in under ground mines but gasoline engines no mater how small our clean burning, our not allowed under ground.

stlrj 09-03-2005 06:32 AM

If I'm not mistaken, oil is a hydrocarbon just like unburned gasoline and somehow I have a hard time believing that the smog equipment would be able to distinguish the difference.

Joe

PatrickB 09-03-2005 08:13 AM

Quote:

Originally posted by Steve87-911
So I hooked up the O2 sensor and took her for a 35 min drive...got it nice and warm.
Came home at let it idle for 3 or so minutes (like at the smog station) and no smoke! After idling that long if I then rev it up I get a couple puffs and it clears right up. So next week I'll go to the smog station again. Crossing fingers.

O2 sensor find Couldn't have come at a better time.... Watch your MPG climb a mile or two as well:D

ficke 09-05-2005 03:27 PM

Stlrj, Next time you go to have your car smogged look around hopefully you will see a diesel being checked, they do not use the same analyzer on a gasoline car, there is a reason for it, They do not produce CO or HC.
I do believe Diesel fuel is a hydrocarbon also. Right now the only thing Diesels or checked for is "opacity" Basically how thick the smoke is.
I am not a chemist so we will need some one else
to chim in if you need a more in depth education on pollution caused from burning different fuels different ways.
or maybe look it up on the Internet. As for a gas car burning engine oil, What it is really letting you know is the health of the engine.
But the actual oil buring is not going to screw up your readings. I hope this helps.

Steve87-911 09-07-2005 05:27 PM

Tomorrow I'm going to try again. I put some lower octane in it (87) and a big ol bottle of techron and drove the pi$$ out of it today.
With the oxygen sensor reconnected it doesn't run as smoothly as before, but then it doesn't smoke at idle either. When getting on the throttle I get the slightest hesitation at about 3800 rpm and the rest of the power band is ok. Maybe it's a slight vacuum leak, I don't know. (any guess?)

I found a different smog check place that gives a free re-test within 30 days if it fails again so I'll try again and if it fails I'll go have it checked out by someone with more p-car smarts than me.

Hoping I didn't kill the cat by putting 10k miles on an unplugged oxygen sensor.

Joe Bob 09-07-2005 05:50 PM

Hey I tole you already Jefe...disconnect one of the injectors....

Steve87-911 09-07-2005 09:18 PM

Thanks for the tip.

Edit: I got it now.

wholberg 09-08-2005 10:11 AM

Quote:

Originally posted by ficke
Stlrj But the actual oil buring is not going to screw up your readings. I hope this helps.
Hydrocarbon failures mean unburned gasoline is passing through the engine and entering the exhaust. The three most common causes include ignition misfire, lean misfire and low compression (typically a burned exhaust valve). Ignition misfire can be caused by worn or fouled spark plugs, bad plug wires or a weak coil. Lean misfire results where there’s too much air and not enough fuel, so check for vacuum leaks, dirty injectors or a fuel delivery problem. In addition to these, hydrocarbon failures can also be caused by oil burning due to worn valve guides, valve guide seals and/or rings.

The real difference between unburned gas and oil is degree. If your engine burns 1 qt of oil every 300 miles, at 15 mpg is also burns 20 gallons, or 160 quarts of gasoline. At idle the contribution of bad rings, valve guides, etc, should be small compared to the amount of unburned gas from one of the causes above, though it could push you over the edge if it is really bad. I had a '68 Camaro that burned 1 qt of oil every 50-100 miles, and it still passed emissions.

All that above was just for information. I'll bet plugging in the O2 sensor fixes it.

Good Luck.

ruf-porsche 09-08-2005 10:42 AM

Quote:

Originally posted by Steve87-911
Thanks for the tip.

Edit: I got it now.

Went to get the garage queen smog last year, had one injector that was slightly stuck, boy thay was the best smog report since I owned the car.

After the test I got the injector unstuck by rapping on it with a punch and dead blow hammer.

3.0 cis system,

you could disconnect one of the injector prior on your dme engine and that cyclinder will act like an air pump.

dandrews64 09-08-2005 10:50 AM

gotta ask: how do you disconnect an injector without spraying fuel all over the place?

DaveE 09-08-2005 11:55 AM

You just disconnect the plug to the electronic injector. You leave the fuel line intact.

dandrews64 09-08-2005 11:58 AM

Thanks Dave. Learn something new about this car almost everyday !


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