Carburated 3F failed emissions...

[DFXR]

Are they checking your timing at each inspection? I ask because without EGR, I'm thinking the only way to reduce your NOx would be through a timing adjustment, likely retarding it. You're pretty close. If they're not checking the timing you could take it out of spec for the test.

The denatured alcohol trick noted above could get your C0 down. It has worked for me when I was close but not quite there. 10 gal gas to 1 gal DA was the rough ratio. It's gonna have more of a kick that just e85.

Lastly, can you do a "pre-test" at your smog shop? Meaning they read your tailpipe numbers but without linking to the statewide computer. That way you can get a read on where you're at without risking an official failure. In CA most smog places will do it for $20, and there's nothing illegal about it.

 

[Honger]

Are they checking your timing at each inspection? I ask because without EGR, I'm thinking the only way to reduce your NOx would be through a timing adjustment, likely retarding it. You're pretty close. If they're not checking the timing you could take it out of spec for the test.

The denatured alcohol trick noted above could get your C0 down. It has worked for me when I was close but not quite there. 10 gal gas to 1 gal DA was the rough ratio. It's gonna have more of a kick that just e85.

Lastly, can you do a "pre-test" at your smog shop? Meaning they read your tailpipe numbers but without linking to the statewide computer. That way you can get a read on where you're at without risking an official failure. In CA most smog places will do it for $20, and there's nothing illegal about it.

They don't check the timing... not sure they'd know how.

NOX went down quite a bit with the work I did... just not down enough. That's probably due to the catalytic converter.

The timing was right at Top Dead Center after I did the valve job... and I advanced it to the factory spec 7-degrees BTDC before this test.

My current thoughts are that the carb has probably never been rebuilt or really adjusted. The only thing that may have been done to it is setting it richer to keep it running well enough. A solid carb rebuild and a good lean-drop tune would probably do wonders for the CO.

I'm working the classic insurance option right now... and if that doesn't pan out I'm going to lean-drop the carb as-is and take some inspiration from the story above.

 

[Honger]

Classic insurance worked out...

This buys me time to get things sorted properly. I've got the carb SST on the way. And I'm still entertaining thoughts of going TBI. At the very least I think I will go Pertronix...

I'll update this thread down the road when I do pass my emissions test.

 

[BK70]

Any update on this, did you get it to pass? I don't need to meet emissions in NY with my 86 carb 3F but I am about to replace the exhaust and do want to make it as clean for the environment as possible. I am also about to rebuild the engine and swap carb for Holley Sniper, and add Pertronix and headers etc. What would you recommend?

 

[Seth S]

Just had a thought in this project....propane conversion?

 

[toastyjosh]

Ok I will say that fuel injection is great and would solve a whole bunch of your issues, plus long term you will love it.

PRODUCTS - FiTech Fuel Injection

Please Read the Following Terms and Conditions of Use Carefully Before Using This Website. Request a Quote

fitechefi.com

That being said your on the right track with the lean drop method, and once you get that with some 91 you should be there.
Also check all of your vacuum lines, I also sea foam every rig before I take to smog check.
Another option is to retard your timing a few degrees and see if that helps.
Good luck!!

 

[Honger]

Any update on this, did you get it to pass? I don't need to meet emissions in NY with my 86 carb 3F but I am about to replace the exhaust and do want to make it as clean for the environment as possible. I am also about to rebuild the engine and swap carb for Holley Sniper, and add Pertronix and headers etc. What would you recommend?

Sorry, missed this somehow.

I've not gotten it to pass. Since I went classic insurance and I'm registered for 2 years it hasn't been a pressing issue. I've not gone fuel injection or pertronix yet... have been focusing on seatbelts, bearings, and brakes at this point.

I still need to do a lean-drop tune on the carb and see what I come up with. I will say that the catalytic converter I welded in has worked well so far. It doesn't get appreciably hotter than the rest of the exhaust at this point.

Going to the Holley Sniper I think you'll be putting in two O2 sensors, right? I'd recommend you put in a catalytic converter at the same time.