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Chris
Chris, Auto Service Technician
Category: Car
Satisfied Customers: 12739
Experience:  43 years of automotive repair, Smog license
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american motors corp. concord: im trying to pass smog with

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im trying to pass smog with my 1978 amc concord. failed first time. uses oil, got little smoke only at start up. runs pretty good overall. did a compression check. I believe the valves are at fault. what could i do to cut down the oil consumption,help with the leaking valve guides and maybe get this ol girl to pass smog?

Hello and welcome to Just Answer. What were the HC, CO, and NOX readings from your smog test?

Chris

Customer: replied 4 years ago.

at 15 mph... hc wasmax 210/gp403/meas174....co was max1.35/gp2.95/meas3.75....no wasmax1350/gp2529/meas626

Ok, thanks. It looks like you failed in CO only. The problem is with a fuel mixture that is too rich. This is a carburetor problem. Although the valve guides and valve stem seals are worn, and causing the oil burning, it did not cause the CO to be too high. What needs to be done is to have the carb rebuilt, or adjusted. A fresh Oxygen sensor may help also. If the catalytic converter is the original one, you may want to have that replaced also. As far as the oil burning, replacing the valve seals will probably help that. I recommend replacing the valve seals and having the carb adjusted/replace, or rebuilt. Then try the test again. If it still fails, replace the cat. I am a smog tech in California, and that is how I would approach this.

I hope this information helps, and let me know if you need further assistance with this.

Chris

Customer: replied 4 years ago.

i know id be the biggest cheater, but would running 10w40 high milage oil with a bottle of "guaranteed to pass"for the fuel system and new plugs be a complete waste of time?

You know, it may help, but I would at least try to get the carb adjusted also. The "guaranteed to pass" additive may not help with the CO, but give it a shot.

Chris

Customer: replied 4 years ago.

also id like to add that the smog shop ran a pre check and it passed but when california asked for dynometer thats when it failed. is there an additive you would recommend to get co down? i like everybody else want easy first before i go with your initial recomendation which by the way did seem very feasible

Well, to be honest with you, I do not think any additive will reduce CO, so keep that in mind. What I recommend is to at least try to get the carb adjusted, and then get the engine good and warm (drive on the freeway to get the cat good and hot) before the next smog test.

Chris

Customer: replied 4 years ago.

i was told that it also helps to go for a smog check when the air temperature is cool. Is there any truth to that one?

Yes, but only if the NOX is too high. Your NOX is within the limit, so that would not be a factor.

Chris
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Customer: replied 4 years ago.

hi chris, i decided to replace the carb but im having allot of trouble identifying it. one thing im sure about it is a carter carb but the numbers i got off the tag and the numbers im finding for the rebuilt carb are not jiving. the number on the tag was 73186 m7 2a. is this a special california smog legal carburetor?

Hmmm, I do not know. I do not have access to a data base that would help me identify that carb. Hopefully your auto parts store can help you with this.

Chris

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