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help my 77 pass smog!

First thing you will want to do is find a quadrajet with all the vacuum line attachments and get all that hooked up.
I have a 77 blazer with a 400 and ca emissions it has no cats or egr just A.I.R.
 
38377k5 said:
X2

And there was no emissions equipment on trucks with a GVWR over 6000 until a couple years later; a 4WD '77 K5 generally had a curb weight of 4700 plus its rated for 1500 pounds in the back, hence a 6200 lb GVWR and no emissions equipment (at least outside of CA).

I bet CA did implement emissions sooner, so you'll probably need to figure out what was there (catalytic converters, AIR pump, EGR, stuff like that)
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+1 on this. My 77 K5 Blazer only has an AIR pump for smog. No Cats, no EGR, ETC., because of the 6200 GVWR.

Of course when I bought it the engine had an EGR, but I HAD to remove it to pass the visual inspection. They would not pass my Blazer with an EGR installed!!!! Stupid CA smog rules.

Your crankcase breather should vent into the air filter housing.

THOUGH... when I used to have to go smog my Blazer it would take about an hour to an hour and a half because there are no cats. Seems that every smog tech thinks that EVERY vehicle 1975 and newer has them. I carry lots of paperwork from GM that I got years ago. Then I have the smog tech search in their books to match up the their smog schematics to my Blazer/GM paperwork. Once they have the right page and are convinced that I am not trying to pull a fast one they will smog my Blazer. In the past few smog checks I finally just started taking it to the same place each few years and the tech guy actually remembers my Blazer. So now the smog checks are a little faster.
 
stillnotbob said:
+1 on this. My 77 K5 Blazer only has an AIR pump for smog. No Cats, no EGR, ETC., because of the 6200 GVWR.

Of course when I bought it the engine had an EGR, but I HAD to remove it to pass the visual inspection. They would not pass my Blazer with an EGR installed!!!! Stupid CA smog rules.

Your crankcase breather should vent into the air filter housing.

THOUGH... when I used to have to go smog my Blazer it would take about an hour to an hour and a half because there are no cats. Seems that every smog tech thinks that EVERY vehicle 1975 and newer has them. I carry lots of paperwork from GM that I got years ago. Then I have the smog tech search in their books to match up the their smog schematics to my Blazer/GM paperwork. Once they have the right page and are convinced that I am not trying to pull a fast one they will smog my Blazer. In the past few smog checks I finally just started taking it to the same place each few years and the tech guy actually remembers my Blazer. So now the smog checks are a little faster.
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well that must be nice .... in albuquerque they dont care what your vehicle came with OE .. if its 75 or newer you gotta pass ,cats and all
 
If the tag is still on the core support, it will say catalyst or non-catalyst, that's the definitive answer. IF it's still there. :(
 
*IF* original engine/drivetrain, the presence or lack of catalytic converter is proven by the sticker. To add or remove a catalytic converter from a drivetrain certified with or without (just like the EGR comment above) is against federal law.
 
I'm gonna hijack real quick.

Since I have converted to TBI now from a 91 suburban it had no A.I.R. only EGR will I have to run a cat in my 77 blazer which came factory with none?

End of hijacking...
 
Yes. You cannot add or remove. If you swap engines, you must also swap all emissions components that came with it, and you can never go backwards. (IE swapping a 1973 454 into a 1985)

State and Federal law typically varies, however violating either one is still breaking the law. Not likely anyone is ever going to check on the Federal side though.
 
update

Thank you all for your support and ideas. I got everything I needed to pass visual, and Im good there, no cats and all =). They ran the smog test on it and it failed due to excessive hydrocarbon emissions.

The tech told me my timing is bad, and I need to adjust carburator. First thing Im gonna do is check my plugs and make sure none of them are fouled. Other than that Ive never adjusted a carb or messed with a timing light, but tallyho Ive got the book here I go!
 
anything older than 75 is emissions and inspection exemt in ca.doesnt help you though.you sho0uld check and see what the tech tells you it needs and then retest it after you replace what it needs.putting in cats would probably make it pass.
 
Outlaws77 said:
Just bought a 77 Cheyenne, dont know much about anything yet, Ive been workin on helicopters for about 6 years so I know how to turn wrenches, but I couldnt point to much on a truck engine. Anyway the truck hasnt been registered since 05, and I got it temporary tags until I get it to pass smog (california). Im ready to drive it down there but I dont want to waste my money if it is going to fail visual inspection. Its got a rebuilt 400sb w/ edelbrock carb,air cleaner. Its got 3" exhaust w/ flowmaster muffler, no cats. It has an empty hole in the manifold where a heater hose would go. Its also got a filter on the crankcase vent instead of what would normally go there. without posting a picture is there anything yall would say I need to do before driving it down and getting it tested? Appreciate any input yall could give me. Thanks.
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The 1977 was the last year without a catalytic converter, so if it didn't come that way new, I don't know how they could require you to install one. Mine doesn't have one.
 
Ancient4X4 said:
The 1977 was the last year without a catalytic converter, so if it didn't come that way new, I don't know how they could require you to install one. Mine doesn't have one.
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I think he's saying that it will cover up for other issues and make it pass the sniffer, which it probably would. Try the plugs, timing, adjustments first, but if it still won't pass you could get a cat put on and probably sail right through.
 
OMG! You have an 85 vehicle and got historic plate designation so now there's no emissions testing for you? You're in Arizona right? I have a 1985 K20 and the previous owner jacked the hell out of the emissions. No catalytic converter, hoses are all over the map, in other words, its a ghetto mess! I'm definitely going to look into this. THANKS!
Phxbare
 
Shoot. I just checked out the DMV and this is what they have about obtaining an historic plate:
Historic Vehicle
$25 initial application fee/ $10 annual renewal. Vehicle must bear a model date of original manufacture that is at least 25 years old. May require a vehicle inspection. Also available for motorcycles.
 
phxbare said:
Shoot. I just checked out the DMV and this is what they have about obtaining an historic plate:
Historic Vehicle
$25 initial application fee/ $10 annual renewal. Vehicle must bear a model date of original manufacture that is at least 25 years old. May require a vehicle inspection. Also available for motorcycles.
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only problem i have with historic tags (in NJ) is you can only drive on certain days.... to and from events.. .and not at night.. I dont want those restrictions..... ill pay more to enjoy my truck.. (when it is back together!!!!)
 
I know that one. I was actually thinking of moving to Black Canyon City so I'd be able to skip emissions!! I need to find a connection to hook me up! lol
On another note, does anyone happen to know where I can get hose schematics for my 85 K20? I got hoses going everywhere. Mine has no cats and an AIR pump, but I know the hoses are messed up.
 
throttleissues said:
I think he's saying that it will cover up for other issues and make it pass the sniffer, which it probably would. Try the plugs, timing, adjustments first, but if it still won't pass you could get a cat put on and probably sail right through.
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yep thats what i was saying.cats collect a lot of the bad emissions that comes from the engine.it sux but its true.the emissions for a 77 truck could not be that high compared to a newer vihicle,as regs do change for each vehicle and year of manufacture.but doing a complete service will definitely help to cut down on hydrocarbons coming out of the engine.the carb and timing being the most essential to have correct.running high octane fuel helps cut emmisions also because of the better heat and burning ability of the fuel and additives to run cleaner.so maybe run a couple of good tanks through the engine before going in to see the sniffer again.good luck.
 
I had a buddy of mine come over and we were tinkering around, inspecting plugs, cap and rotors when he discovered an empty vacuum fitting between the carb and the distributer on the intake manifold. We plugged it up and I noticed an instant performance increase and sound difference. My only concern, is what is that vacuum fitting supposed to supply vacuum to? Could it have gone to the automatic transmission that was replaced by a manual?
 
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