Help with Weird Emissions

[chevyaddict]

Hi everyone. Took my 81 through emissions today and had great HC readings both at idle and load, had VERY LOW CO emissions at idle but failed CO under load.... what in the world would cause such a reading? Any advice would be helpful.... what should I adjust? My guess this is a carb issue..... cat, EGR and smog pump are not that old.... timing is also right on. She is running great!

 

[chevyaddict]

Ok... I've just spent a bunch of time searching the other emissions posts but none of them has my particular problem! It seems most people fail the HC test on these forums and that is not my problem. HELP! I need interpretation of what a Hi CO reading means under load only!!!

 

[geekinavette]

Possibly catalytic converter. The cat con converts CO (Carbon Monoxide) to CO2 (Carbon Dioxide). Check the CO2 readings....if CO is very high and CO2 is very low, then the cat con is likely failing.

 

[chevyaddict]

Nope- new cat was put in two years ago and the car has been driven maybe 2000 miles since then..... but thanks for that suggestion!

Hey though..... NEVERMIND ON THIS!!! I've decided to just put classic car insurance on it and get it emissions exempt! Problem solved!!!!!!!!!!

 

[Yoda]

Nope- new cat was put in two years ago and the car has been driven maybe 2000 miles since then..... but thanks for that suggestion!

Hey though..... NEVERMIND ON THIS!!! I've decided to just put classic car insurance on it and get it emissions exempt! Problem solved!!!!!!!!!!

Tongue in cheek:
What about "Global Warming" hnoes

Bud

 

[chevyaddict]

I know I know...... I'll probably still tinker with it to figure out the problem but I'm pretty sure its just a tired carbureator and I don't have the mula to rebuild it or buy a new one at the moment.

 

[Mr. Chuck]

I know I know...... I'll probably still tinker with it to figure out the problem but I'm pretty sure its just a tired carbureator and I don't have the mula to rebuild it or buy a new one at the moment.

Is your Carb the original one? If so has it ever been worked on / rebuilt?
My 81, which I bought new, always passed SMOG until last year, when it failed big time.
The original Carb which had until then only received minor cleaning, some new gasket set ever few years & periodic checking for loose screws from shrinking gaskets. The problem / solution was to replace the varies electrical control components that had worn-out and were sticking / binding, etc. Bottom line they weren't responding to the ECM signals properly. After a total rebuild by an old time Ex-GM Mechanic (owner of a local shop), my 81 now has SMOG readings like when it was new. Additionally it starts 123, run very smooth and has plenty of power again.

 

[chevyaddict]

Is your Carb the original one? If so has it ever been worked on / rebuilt?
My 81, which I bought new, always passed SMOG until last year, when it failed big time.
The original Carb which had until then only received minor cleaning, some new gasket set ever few years & periodic checking for loose screws from shrinking gaskets. The problem / solution was to replace the varies electrical control components that had worn-out and were sticking / binding, etc. Bottom line they weren't responding to the ECM signals properly. After a total rebuild by an old time Ex-GM Mechanic (owner of a local shop), my 81 now has SMOG readings like when it was new. Additionally it starts 123, run very smooth and has plenty of power again.

Has never been rebuilt and desperately needs it... the secondaries aren't even opening at this point. When there is money perhaps I'll get that done but not right now! I ended up getting around this by putting classic car insurance on it and by-passing the emissions process. hee hee

 

[Mr. Chuck]

Looks like you know what to do! In the mean time here hoping it doesn't strand you somewhere when if it fails to start. A rebuilt done right, will amaze you how well the vette can run, besides the improvement in MPG, check out you tail pipes, if they are black (clear sign that you are running rich & wasting fuel), ligh grey shows a nice lean fuel / air ratio.

 

[TMPJoe]

mine has been exempt now for a few years.. i drive it 600-800 miles a year and everytime i pass a poster about polar bears I feel so guilty... then I see a prius with its Chinese made battery and think about what went into that and i feel so much better!

I calculated I fart more gases annually than my vette puts out

 

[chevyaddict]

i calculated i fart more gases annually than my vette puts out

;lol