Passing CA Smog help - High HCs

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fast 99

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CO isn't extremely high suspect problem lies somewhere besides carb

Some items to look at:

internal engine wear and or misfire
vacuum leak, remember they can leak under intake
stuck EGR if equipped
over advanced
camshaft with too much overlap
overheating
 

Bextreme04

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At least some of that is not accurate. Federal emissions in a 1980 8600GVW K25 with a 350 did not have an AIR pump and injectors going into the manifold. It's even more interesting that the maker of that manual is her in Troutdale, OR and my truck was originally delivered to the Beaverton GMC/Buick dealer here in 1980.
 

Ncali

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Elevated hydrocarbon (HC) emissions usually indicate ignition misfire due to fouled spark plugs or a bad plug. But high HC emissions can also be caused by burned exhaust valves (check compression), lean misfire (check for vacuum leaks, low fuel pressure or dirty injectors), or rich fuel conditions (fuel saturated carburetor floats, excessive fuel pressure, leaky injectors or a dead O2 sensor).

High carbon monoxide (CO) emissions are a telltale sign of a rich fuel mixture. On older carbureted vehicles, fuel-saturated plastic floats, incorrect float settings, leaky power valves and misadjusted chokes are often responsible for the rich mixture. On newer vehicles with feedback fuel controls and fuel injection, leaky injectors, excessive fuel pressure and sluggish or contaminated O2 sensors are all possibilities to investigate.

Harder to diagnose are elevated oxides of nitrogen (NOX) emissions. Causes here may include a defective EGR valve, EGR vacuum solenoid or motor, plugged EGR ports in the manifold, over-advanced ignition timing or engine overheating.
 

Ncali

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everything you put on the truck has to be carb compliant so that carb you put on may not pass
 

DoubleDingo

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everything you put on the truck has to be carb compliant so that carb you put on may not pass
I was thinking the same thing
 

77Matt

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everything you put on the truck has to be carb compliant so that carb you put on may not pass
Why would it need to be carb compliant. Would they even know to look under truck if the doc says not applicable? It doesnt make sense to need a compliant one if it isn’t needed for that model year- it’s just extra
 

Ricko1966

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Why would it need to be carb compliant. Would they even know to look under truck if the doc says not applicable? It doesnt make sense to need a compliant one if it isn’t needed for that model year- it’s just extra
He said carbureator may not pass,and I had the same feeling. Used to be it had to be legal replacement not just any carbureator you picked up. I used to fail the obvious ones on visual. And people don't understand,when the inspectors fail things he's not being a dick,he's keeping his job and his income. He doesn't know you or your vehicle from Adam.
 

77Matt

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He said carbureator may not pass,and I had the same feeling. Used to be it had to be legal replacement not just any carbureator you picked up. I used to fail the obvious ones on visual. And people don't understand,when the inspectors fail things he's not being a dick,he's keeping his job and his income. He doesn't know you or your vehicle from Adam.
Oh lol- the carb is CA approved. It came with a doc I’m supposed to give the tester.
 

CalSgt

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Oh lol- the carb is CA approved. It came with a doc I’m supposed to give the tester.
A lot of California Air Resource Board AKA “CARB” approved parts come with a decal that either goes on their part or on the core support. The sticker has an Executive Order “EO” number on it for the tech to look up so they can confirm the part is legal.
 

evlblkrfl

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I'm about to go through the same thing. I have a 77' K20. I was looking at that Edelbrock carb too but I'm really thinking about going with the MSD fuel injection instead.
 

77Matt

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I'm about to go through the same thing. I have a 77' K20. I was looking at that Edelbrock carb too but I'm really thinking about going with the MSD fuel injection instead.
I was going to go fuel injection but was told I would fail inspection if I didn’t have a carb. Just by a car guy not someone with testing experience
 

77Matt

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everything you put on the truck has to be carb compliant so that carb you put on may not pass
The info I have is that it’s legal in ca on GM v8s prior to 1980. I hope that info is legit. Praying to the truck gods. Hopefully I receive all the parts so I can smog next week. Ready to get the project rolling-legally. Wifey doesn’t want a lawn/driveway ornament.
 

evlblkrfl

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The MSD 2900 Atomic EFI is the only fuel injection kit that has an EO # for use in California
 

Finkaire

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I had my original electric carburetor rebuilt, i was told that was the only option.
 

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