Failed CO emissions-high CO and HC

[MikeB]

For TX I assume you are talking about Antique plates.

Yes, especially now that they don't look goofy! I've used them on two trucks and a car since around 1998.

Funny, but we lived in Colorado for 4 years in the mid-90s. I don't ever remember getting an emissions test on my 69 pickup. We must have left before all the craziness started.

For every vehicle over 25 years old, I'm guessing there are thousands of newer ones that have all the latest emissions control technologies. So you have to wonder if the percentage of CO2 emissions from the older vehicles is even significant. I read a story somewhere that it's less than 0.1%, at least in the US. I also read where the United Nations says low and middle income countries have lower standards or none at all. And those countries tend to buy shiploads of older, used vehicles from more advanced nations. That means old car and truck hobbyists in the USA must suffer to compensate for poorer countries.

 

[squareton]

EGR has been MIA since back in 'Nam and I'm 99% sure the Edelbrock intake that's on it now is non-EGR. Ive only had the truck since the beginning of September and haven't had a whole lot of time to get real intimately familiar with it yet because we also took a week long vacation since then. I'll grab an IR gun in the next day or two and check the cat and probably pull hoses off the pump tonight. It is also a bit inconvenient to get to this specific test center unless I downsize tires. That was also a backup plan I had was to throw on a cheap set of CL 31's just for testing. I would imagine lighter/smaller tires would bring emissions down across the board and I could go to the place that's 5 minutes from my house after a nice warmup. Depending what I can get worked out in the next few days I may make another trip up since a retest within 10 calendar days is free.

I thought i was the only one who says back in nam hahahaha

 

[Manny_Santana]

Hey all,

Hate for this to be my first post here but I just failed emissions pretty miserably and need some advice. CO was at 137, limit 40 and HC was at 4.9, limit 4.0. Test was on IM240 treadmill.

Basics about the truck: Bought it at the end of september, it's an 86 K10 350 on 35's not sure what gears, originally had CA emissions. I recently hooked the smog pump back up in anticipation for testing. EGR is long since gone. Has one cat after Y that does not appear to be original but is stamped CARB compliant. Carb is a Carter AFB. Decel valve that connects to charcoal canister appears to be missing also. I'm not sure how well any of the valves/solenoids related to emissions work at the moment. Based on the 30 some year old temp guage, I believe someone put in a colder t-stat since the guage stays right at 175*. I'm assuming replacing this with a 195* would help?

I think the high HC can be fixed with a good tuneup (plugs, wires, cap, coil, rotor, LOF) and maybe a new cat if necessary. I know high CO is caused by excessive fuel. At this point, am I limited to rejetting (which I don't know how to do but could probably learn) or going FI? Or start with a rebuild(again, could learn)? I do get a slight fuel smell when I shut it off which leads me to think it may be in need of a rebuild. I also have a rebuilt, unused Quadrajet that the PO gave me but I would need to get a Quadrajet intake. Am I on the right track or does anyone have any advice they care to share? I would really love to not have to turn around and sell this truck just because I can't get it to pass emissions.

I would really start with what actually came originally on the truck or engine bay and what was swapted out.
IDentify what was originally on truck...
What is missing...
What was replaced....
And what it has now....
You can STILL PASS SMOG WITH 33's wheels or whstever is on it but it comes down to this, the truck being tuned to specs accorxing to its year and model. Tgat means ypu gptta take a vaccum gauge and per the label on the truck engine bay it will tell you like....
Most trucks from 78 or 79 thru 88 are 6° degrees before top dead center @ 600 rpms while on drive with AC ON and emergency foot brake and blocked or someone behind the driver seat holding brake down @ iddle.
This is when your vaccum gauge is put and if it is not on green closest to center of green than it needs to get to that.
Whst will help this is a regular tune up "COPPER SPARK PLUGS" not thst other hitech spark plug like platnums or iridiums these are for higher hotter spark gm engines are not that period. Carburator in Cali where all quadrajets overall and make sure it is tuned up right with possible rebuilt needed.
After that run regular unleaded with maybe half tank of fuel with cataclean and run the dang truck NON STOP FOR 100 MILES EACH DIRECTION AND I CANNOT EXPRESS THIS ENOUGH 100 MILES NON STOP AT ABOUT 75MPH NOTHING LESS. WHY YOU ASK Because it needs to burn off all contaminants from the combustion chamber.All the way down to the downpipe into the Catalytic converter. Once you do this Go ahead and Check your spar plugs again, make sure they are not burnt or covered again in gunk, and if the yard swapped them out before you smog it, your spark needs to be good, so you don't have a hitnmiss aka sputtering or faurt like popping while in idle. Gm engines after 50k miles had a very light tone of sputter but not too noticable and overall sounds was like a cat purring when engine was at idle and warm engine. All my tuned cars n trucks i have left like this. Folks ask how i know all this anxx im in my 46 years old well i was shown well by greese monkey uncles who owned shops in East Los Angeles in the early 70s n late80s and they loved all ratrods n lowriders n classic restos.
So i do rebuilt carbs to from 1930s to 80s
anyways hope this helps sòme