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Passing smog

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Old 01-28-08, 08:47 PM
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Passing smog

Just got a smog test done, HC was up around 1600 and CO was at about 4.8

Well above the allowed 150 and 1.0, any suggestions?
Old 01-28-08, 08:57 PM
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Originally Posted by MDittz2ndGEN
Just got a smog test done, HC was up around 1600 and CO was at about 4.8

Well above the allowed 150 and 1.0, any suggestions?
You're in worse shape than me, but your CO is in my ballpark. I'm hoping that a new O2 sensor will solve the problem, cause the rest of my car should be clean.

good luck...
Old 01-28-08, 09:04 PM
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Try the FAQ next time:
Originally Posted by FAQ
My car is having trouble passing emissions, but I have new spark plugs, filters, cats, etc. What do I do?
Check your air pump (air injection). You might also be running rich, but if you car was that rich it probably wouldn't be running too well.
Old 01-28-08, 10:22 PM
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I'd say you need a new cat.
Old 01-29-08, 12:26 AM
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Actually it has been running really rich, how would I check my air pump/injection system?

Also, I'm getting my car smogged again by the end of the week. The moron that did the smog had all kinds of trouble searching through the engine compartment for the (EGI?) valve, and then decided to do some other test because he couldn't find the valve. The car was on idle for like an hour and a half before he took the emissions test, the ******* went through a quarter of my gas tank and still charged me for the test even though it took 2 and a half hours and didn't pass, I'm going back tomorrow to get a refund from the manager.

It's been smogged plenty of times, this is the first time that it didn't pass so I'm going to take it to one of the places it's been smogged previously, hopefully that'll make all the difference. I'd still like to check out why the car's running so rich though, how would I do that?
Old 01-29-08, 12:42 AM
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What kind of maintains have you done lately? If the smog tech have problem finding the EGR you can just point it out for him so he can go on with his test. (Is under the manifold)
Old 01-29-08, 12:59 AM
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As you're facing the engine the air pump is that thing on the left (passenger side). It's driven by a belt It has a tube going to the cat. Make sure it's spinning, make sure the belt tension is good (~1/2" deflection if u push the middle), make sure the tube is connected, etc. Dunno what else to check, try searching.

A new cat won't help until this is fixed, unless your NOx is very high too.
Old 01-29-08, 03:57 AM
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i heard u can premix ur fuel with denatured alcohol, it make the fuel leaner, and the engine would run alot cleaner..I dont know if this is safe on rotaries tho...
Old 01-29-08, 06:09 PM
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I take it your results are for the idle or low speed test?

It sounds to me like no "split air" (Mazda terminology) is getting into the catalytic converter.

A fairly complex system (consisting of the air pump, air control valve (ACV), solenoid valves, and data from sensors) is responsible for determining whether air is pumped into the main catalytic converter ("split air"), the exhaust port ("port air"), or back into the atmosphere ("air relief" or "bypass").

If you look underneath the car on the passenger side, you should see a thin metal pipe parallel to the exhaust that ends at the cat, where they are connected by a high temperature rubber hose. Sometimes, this hose melts / frays / disintegrates and the "split air" is dumped into the atmosphere instead of the main cat.

The air pump itself is fairly simple to test. From your air cleaner box, next to the main intake tube, you'll see a small hose that delivers filtered air into the air pump. Disconnect the hose at the air cleaner. If your air pump is working, you should feel air getting sucked in. If you add throttle, the suction will be stronger. (Alternatively, you can check to see if air is flowing out of the air pump at the other end, but that hose is much more difficult to remove and reconnect).

The Hayes manual gives a fair overview of testing the emissions components, but it's nearly impossible to identify some of the solenoids. The FSM is more thorough and authoritative.

BTW, your numbers are not close enough to use the alcohol trick.


Reference Information:

ACV Function:

http://howto.globalvicinity.com/gv_w...i=73&co=1&vi=1

FSM:

s4: http://www.cochran-racing.com/FSM/s4/
s5: http://www.cochran-racing.com/FSM/s5/


s4 emissions (s5 similar):

http://mazdarx7.iougs.com/emissions.shtml

Helpful threads:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/cheap-easy-emissions-568471/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/emission-testing-texas-style-465422/
Old 01-29-08, 06:55 PM
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I'll go ahead and check the air pump right now and take a look at that hose running to the cat. while I'm at it. I'm going to get it smogged again at a place that I know is respectable and see if there's a difference, hopefully it'll pass fine. The car's definitely running rich, I'm going to check out the pump & all that nonsense but if nothing's there to fix then I'm going to replace my fuel injectors, and my ECU as a last resort. If I replace the ECU, would you guys recommend just going with a performance replacement (street ported engine) or the stock ECU?
Old 01-29-08, 09:25 PM
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just a quick Tip..Rotary engines EAT catalytics..if the car has the Original Catalytic on it,then it is most liley Baked beyond belief..or hollow...and some owners like toHollow the damn thing out to get that 2 HP!(I spent Money on an Etest only to Find out the cat was Totally EMPTY..DUH!).A good Hi-Flo Cat will work wonders.
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