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sean
03-13-2000, 01:05 PM
My car ('82 733i) failed CT emissions twice for NO2 emissions - max allowed is around 1100ppm, my car read around 1400ppm. CO and HC were low.<br>I replaced the O2 sensor when it failed the first time. The DOT suggestions are: O2 sensor, EGR system, Catalytic converter or high compression from too much carbon buildup.<br>-There's no EGR on the e23 as far as I know. <br>-O2 sensor is new. O2 sensor is a bosch multi fit unit - the wire gets spliced onto the old wire. The old O2 sensor had only one wire as well - seems like it should work.<br>-Car doesn't exhibit any of the signs of excessive carbon buildup (pinging, run-on, loads of stuff out the tail pipe under hard acceleration)<p>How do I check the cat, and is there anything else I should check? I've heard there's an additive that will make a car pass emissions but I'm always suspicious of stuff like that.<p>The valves are due for an adjustment, but if they were hanging open, I'd probably get high HC readings.<p>Any input would be greatly appreciated - Thanks!<br>

Bill Bowes
03-13-2000, 06:17 PM
Get yourself to a BMW shop who has a gas analyzer, and knows what they're doing (that eliminates the dealer). <p>With the doodad up the tailpipe, you should be able to adjust the air flow meter to spec. There is a black cover on the AFM, probably on the bottom. Remove the black cover and you'll see the electronics. And you'll see a notched wheel. with the car on the analyzer, all you do is move the wheel,(don't forget to mark where you started) one notch at a time, until you meet specs. <p>Drive the car around the block, and check it again. Move as necessary. Don't forget to seal the black cover. One drop of water and the AFM is toast. <p>This is assuming that the tuning items, cap rotor, wires, plugs, and valves are properly adjusted. <p>BTW, I've seen cars that were in pretty bad shape get past emmissions by doing the above. If you haven't established a rapport with a local shop, do so. I buy all my parts from mine. Granted I could get them for less elsewhere, but they're more prone to bail you out of trouble, and give you advice if you buy the parts from them. And after awhile, they get to know you, and you'll notice that the parts cost drops. A case of beer now and then helps too, especially on a Friday around 5:00.<p>Bill Bowes

sean
03-13-2000, 06:43 PM
<i>: Get yourself to a BMW shop who has a gas analyzer, and knows what they're doing (that eliminates the dealer). <p>: With the doodad up the tailpipe, you should be able to adjust the air flow meter to spec. There is a black cover on the AFM, probably on the bottom. Remove the black cover and you'll see the electronics. And you'll see a notched wheel. with the car on the analyzer, all you do is move the wheel,(don't forget to mark where you started) one notch at a time, until you meet specs. <p>: Drive the car around the block, and check it again. Move as necessary. Don't forget to seal the black cover. One drop of water and the AFM is toast. <p>: This is assuming that the tuning items, cap rotor, wires, plugs, and valves are properly adjusted. <p>: BTW, I've seen cars that were in pretty bad shape get past emmissions by doing the above. If you haven't established a rapport with a local shop, do so. I buy all my parts from mine. Granted I could get them for less elsewhere, but they're more prone to bail you out of trouble, and give you advice if you buy the parts from them. And after awhile, they get to know you, and you'll notice that the parts cost drops. A case of beer now and then helps too, especially on a Friday around 5:00.<p>: Bill Bowes <p></i>Will this effect NO readings? the car passed for HC and CO - Less air will raise these, more air will lean out, which I don't need to do because of current low HC and CO. is this correct?

Bill Bowes
03-13-2000, 11:27 PM
That's why you need the machine. Every time you make an adjustment, you'll see the results on both planes. I've seen one notch changes take an engine right off the scale. <p>when the machine says you're legal, drive it around the block, and blow it out. Then re-check it. It should still be in spec. <p>My experience is that if all the tune-up stuff is OK, you won't have any wild changes, and the car eally will run better; even if it seemed to be running fine before.<p>This is also why I maintain a good relationship with a shop. I can drive in on a Sat AM, and hook it up. Make sure it will pass, and drive right over, and pass. otherwise I'd have to pay a fortune, and rely on their honesty. At this point I even make the changes. <p>OH. Let's say your engine isn't running quite right. Maybe it needs a valve job. Make the adjustments, pass the test, and then set it back to where it runs well again.<p>Bill Bowes

Bob
03-14-2000, 01:38 PM
<i>: My car ('82 733i) failed CT emissions twice for NO2 emissions - max allowed is around 1100ppm, my car read around 1400ppm. CO and HC were low.<br>: I replaced the O2 sensor when it failed the first time. The DOT suggestions are: O2 sensor, EGR system, Catalytic converter or high compression from too much carbon buildup.<br>: -There's no EGR on the e23 as far as I know. <br>: -O2 sensor is new. O2 sensor is a bosch multi fit unit - the wire gets spliced onto the old wire. The old O2 sensor had only one wire as well - seems like it should work.<br>: -Car doesn't exhibit any of the signs of excessive carbon buildup (pinging, run-on, loads of stuff out the tail pipe under hard acceleration)<p>: How do I check the cat, and is there anything else I should check? I've heard there's an additive that will make a car pass emissions but I'm always suspicious of stuff like that.<p>: The valves are due for an adjustment, but if they were hanging open, I'd probably get high HC readings.<p>: Any input would be greatly appreciated - Thanks!<p></i>--------------------------------------------<br>High NO reading say the combustion temp is too hot (EGR reduces combustion temps). Your CAT is fine or the other readings would have been higher.<p>You cannot retard the timing because of the Motronic.<p>Add 10% ethanol to your fuel ("Dry Gas" fuel system water elimator is ethanol). It will reduce combustion temps to where NO is NOT formed during combustion.<p>Try this BEFORE trying other stuff if you can do a test run on a non-DOT analyzer first.<p>Good luck,<br>Bob

sean
03-14-2000, 05:49 PM
<i>: : My car ('82 733i) failed CT emissions twice for NO2 emissions - max allowed is around 1100ppm, my car read around 1400ppm. CO and HC were low.<br>: : I replaced the O2 sensor when it failed the first time. The DOT suggestions are: O2 sensor, EGR system, Catalytic converter or high compression from too much carbon buildup.<br>: : -There's no EGR on the e23 as far as I know. <br>: : -O2 sensor is new. O2 sensor is a bosch multi fit unit - the wire gets spliced onto the old wire. The old O2 sensor had only one wire as well - seems like it should work.<br>: : -Car doesn't exhibit any of the signs of excessive carbon buildup (pinging, run-on, loads of stuff out the tail pipe under hard acceleration)<p>: : How do I check the cat, and is there anything else I should check? I've heard there's an additive that will make a car pass emissions but I'm always suspicious of stuff like that.<p>: : The valves are due for an adjustment, but if they were hanging open, I'd probably get high HC readings.<p>: : Any input would be greatly appreciated - Thanks!<p>: --------------------------------------------<br>: High NO reading say the combustion temp is too hot (EGR reduces combustion temps). Your CAT is fine or the other readings would have been higher.<p>: You cannot retard the timing because of the Motronic.<p>: Add 10% ethanol to your fuel ("Dry Gas" fuel system water elimator is ethanol). It will reduce combustion temps to where NO is NOT formed during combustion.<p>: Try this BEFORE trying other stuff if you can do a test run on a non-DOT analyzer first.<p>: Good luck,<br>: Bob<p></i>Thanks!<br>How do I solve problem of heat in combustion chamber? I don't think e23's have egr - could it be carbon buildup?

Bob
03-15-2000, 12:34 AM
<i>: : : My car ('82 733i) failed CT emissions twice for NO2 emissions - max allowed is around 1100ppm, my car read around 1400ppm. CO and HC were low.<br>: : : I replaced the O2 sensor when it failed the first time. The DOT suggestions are: O2 sensor, EGR system, Catalytic converter or high compression from too much carbon buildup.<br>: : : -There's no EGR on the e23 as far as I know. <br>: : : -O2 sensor is new. O2 sensor is a bosch multi fit unit - the wire gets spliced onto the old wire. The old O2 sensor had only one wire as well - seems like it should work.<br>: : : -Car doesn't exhibit any of the signs of excessive carbon buildup (pinging, run-on, loads of stuff out the tail pipe under hard acceleration)<p>: : : How do I check the cat, and is there anything else I should check? I've heard there's an additive that will make a car pass emissions but I'm always suspicious of stuff like that.<p>: : : The valves are due for an adjustment, but if they were hanging open, I'd probably get high HC readings.<p>: : : Any input would be greatly appreciated - Thanks!<p>: : --------------------------------------------<br>: : High NO reading say the combustion temp is too hot (EGR reduces combustion temps). Your CAT is fine or the other readings would have been higher.<p>: : You cannot retard the timing because of the Motronic.<p>: : Add 10% ethanol to your fuel ("Dry Gas" fuel system water elimator is ethanol). It will reduce combustion temps to where NO is NOT formed during combustion.<p>: : Try this BEFORE trying other stuff if you can do a test run on a non-DOT analyzer first.<p>: : Good luck,<br>: : Bob<p>: Thanks!<br>: How do I solve problem of heat in combustion chamber? I don't think e23's have egr - could it be carbon buildup?<p></i>-------------------------------------------<br>That is the point:<p>Ethanol blend burns cooler-hense less NO.<p>Bob


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