CA smog question [Archive] - Chevy Nova Forum

: CA smog question


f16fxr4real
22nd-May-2010, 11:58 PM
I just got my grandfathers 1977 Chevy pickup and am worried about smogging it.
It doesnt smoke, runs great, and doesnt seem to be running rich or lean.
Ive tried to find information on if it originally had/is supposed to have a catalytic converter because right now it doesn't.
The headers go into a single exhaust which looks to be 2 1/4 and into a cherry bomb type muffler and then the rest of the exhaust to the back of the truck.
Any help is appreciated.

tmoore79
23rd-May-2010, 12:04 AM
I believe all it has to have is a good PCV valve. Go to Autozone, buy a new one and plug it into your valve cover and go get it smogged.

63ssvert
23rd-May-2010, 12:19 AM
Is the decal still on the core support, it will have abbreviations for everything it came with, and must have, to pass the visual.
It's a white decal, black writing, 2"x 6", may also have a diagram of the vacuum/smog hose routing.
Take a picture and pm it to me Adam .

tmoore79
23rd-May-2010, 12:28 AM
I have a 1977 Chevy C20 Custon Deluxe Camper Special with a 350 V8 and a Rochester Quadrajet 4MV (7045583 YZ)

I took it in for a smog check. It output about 7% carbon monoxide, so I took it home and started messing with it. I figured out that some idiot installed the choke coil rod wrong causing the choke to stay on forever.With the engine running super rich, it's no wonder it was putting out 7% CO.

The truck was also lacking power.

Someone also had the timing set to 28 degrees BTDC. Maybe that's what it needed to run properly with the choke on all the time, I don't know. So I set the timing to 2 degrees BTDC like it's supposed to be here in CA.

I brought it back to the guy and he gave me a free check to see what it was outputting now. The CO's were fixed, but now it's putting out 2000 ppm of hydrocarbons.

A friend of mine said that this truck probably doesn't have a catalytic converter but instead has a air injection system. I checked it out, and it does, and it appears to be working. I disconnected one of the hoses that's connected to one of the exaust manifolds and it's blowing air.

I also replaced the distributor cap, rotor, sparkplug wires, all the vacume hoses, the PCV valve (which had a crack in it) and the engine seemed to run a bit better, but still lacked power.

So, I went to the junkard for a new carb. Spent $40, took it home, then as I was swaping linkage parts from the old carb to the new carb, I found that the fast idle cam was installed upsidedown.

I had noticed before that there was no mechanims that would dissable the secondary throttle lockout which would explain the lack of power. (I assume that the same idiot who installed the choke coil rod wrong also installed the fast idle cam upsidedown) When I noticed this, I tried using a small wire to permanently dissable the secondary throttle lockout which didn't seem to help with the power (which I'm still confused about).

Anways, I put the old carburator back together correctly and now the truck has alot more power and runs pretty good, but I'm affraid that it still won't pass smog. I'm about to head out to pick up a tachometer so that I can ajust the idle mixture using the lean drop method, but all I have is this crappy Haynes manual that I picked up at the library that seems to tell me everything about every other truck from 1967 through 1985 except for mine.

In the manual it says that my truck should have the following:
1. Positive Crankcase Ventilation (PCV)
2. Air Injection Reactor System (AIR)
3. Exhaust Gas Recirculation System (EGR)
4. Catalytic Converter
5. Early Fuel Evaporative System (EFE)
6. Throttle Return Control (TRC)

This thing has no catalytic converter, and no EGR. It appears that the exhaust pipes have been worked on, so maybe someone removed the cat, but there isn't even a port on the intake manifold for where the EGR belongs.

This truck must be some sort of special case or something.

Anyways, I'm going to go pick up tach and try to make all the carburetor indicated in the manual for this truck and carb and hope that helps.

f16fxr4real
23rd-May-2010, 12:52 AM
Is the decal still on the core support, it will have abbreviations for everything it came with, and must have, to pass the visual.
It's a white decal, black writing, 2"x 6", may also have a diagram of the vacuum/smog hose routing.
Take a picture and pm it to me Adam .

There is a sticker on the air filter assy lid that says what the idle should be for specific engine size and HP output but then says for emission information, see the separate emission sticker

lugnut
23rd-May-2010, 02:21 AM
I believe 76 on had cats. A 49-state version may have had no cats, so if it started outside of CA, you may be in luck. When you go in for smog, have them pre-test it to see where the readings are.

Chevy Kid
23rd-May-2010, 04:37 AM
Adam, what is it? 1/2T, 3/4T, etc. Years ago my dad had a '77 "heavy half". No cats, no EGR, no air pump. Stock! He had an edelbrock manifold with the correct Q-jet. Passed smog every time.



Tim

69Proof
23rd-May-2010, 05:08 AM
Look for a smog station that will pretest it for you.
Emissions limits were lowered again on the 5th of May.
We had a customers 84 Bronco that we worked on to pass emissions.
If we would have had it tested on the 4th it would have passed.
Good luck...

Nova 404
23rd-May-2010, 11:16 AM
They started using Cats in 74 or 75 on most vehicles,maybe not a 3/4 ton or heavier.Actually I probably have a smog book at work that will answer your question.Let me know by Monday and I will look it up for you.I will be off Tuesday-Wednesday for my daughters wedding

f16fxr4real
23rd-May-2010, 12:44 PM
I need to decode the firewall tag.
I only did the VIN so far and found out that it IS an original 350 4 barrel truck.
I thought the heavy halves had the fender tag that said it?
It doesnt have a really thick leaf spring pack.
Im going to take a pic of the firewall tag and put it on here.
thanks for all the help so far guys.

I may be jumping the gun, but am all excited now. If Im reading the installed equipment tag correctly, it IS a heavy half

f16fxr4real
23rd-May-2010, 01:05 PM
ok, I cant find a stinkin cowl tag.
But it does have this and apparently I do have the TH-400 which the pan does look like, and the higher power 4 barrel 350
http://i992.photobucket.com/albums/af41/zadam/003.jpg

tnblkc230wz
23rd-May-2010, 01:47 PM
I believe 76 on had cats. A 49-state version may have had no cats, so if it started outside of CA, you may be in luck. When you go in for smog, have them pre-test it to see where the readings are.

49 state C10 models had cats from Jan 76 on. Early 76's didn't have cats and the late ones did.

f16fxr4real
23rd-May-2010, 02:23 PM
got under the truck to verify it actually had a TH-400 in it (cause in my head I couldnt remember which was the 350 and which was the 400 pan) and after cking and recking, its a 350.
The pan is the rectangular one with the corner cut off, which matches all the other 350s Ive seen and just verified on a Chevy tranny ID chart. Oh well, smog should still be easier.

6T6NOVA
23rd-May-2010, 04:06 PM
I just got my grandfathers 1977 Chevy pickup and am worried about smogging it.......Any help is appreciated.

Have you looked at the California DMV web site? If your Grandfarther gave you this truck as a gift you might not have to smog it to transfer ownership. A gift from one family member to another.

I think I would check into this before going through all the SMOG test for nothing.

Bryan

f16fxr4real
23rd-May-2010, 10:06 PM
Have you looked at the California DMV web site? If your Grandfarther gave you this truck as a gift you might not have to smog it to transfer ownership. A gift from one family member to another.

I think I would check into this before going through all the SMOG test for nothing.

Bryan

It hasnt been smogged since '05 and hasnt been driven in two years. Im pretty sure this falls under the every other year smog I read about somewhere.

jmdc
24th-May-2010, 12:03 AM
Go to ChevyTalk.org and go to the section for your truck. This is where I go when I have questions on my 81. That site is good and has good people. That is where I was before I came to steves.



-Justin

f16fxr4real
24th-May-2010, 02:10 PM
Go to ChevyTalk.org and go to the section for your truck. This is where I go when I have questions on my 81. That site is good and has good people. That is where I was before I came to steves.



-Justin

I'll ck it out

6NOVA4
26th-May-2010, 06:46 PM
SOME 1/2 ton pickups, blazers and suburbans in Ca in 76 and 77 didn't come with a cat, even though they were 1/2 ton chassis if ordered with heavy duty suspension like a tow package or a camper package it came with a heavy duty 350 or 400.So it only needed PCV, TAC, single EVAP canister and Air injection. NO EGR, NO CAT. 3/4 ton trucks same thing. Big Block trucks needed EGR and Air injection. My 76 GMC 1/2 ton stepside was a Ca truck, no EGR, no Cat, only Air injection. Same for my dad's 76 suburban. Both were heavy duty suspension packages. Any experienced smog tech will know that, also the emissions application book they have should show that too.

Chevy Kid
27th-May-2010, 04:16 AM
SOME 1/2 ton pickups, blazers and suburbans in Ca in 76 and 77 didn't come with a cat, even though they were 1/2 ton chassis if ordered with heavy duty suspension like a tow package or a camper package it came with a heavy duty 350 or 400.So it only needed PCV, TAC, single EVAP canister and Air injection. NO EGR, NO CAT. 3/4 ton trucks same thing. Big Block trucks needed EGR and Air injection. My 76 GMC 1/2 ton stepside was a Ca truck, no EGR, no Cat, only Air injection. Same for my dad's 76 suburban. Both were heavy duty suspension packages. Any experienced smog tech will know that, also the emissions application book they have should show that too.

Exactly! This is what my dad's truck was. An oddball for sure, This truck was from cali and smog legal all the way.

Tim

VooDooII
27th-May-2010, 10:31 AM
ok, I cant find a stinkin cowl tag.
But it does have this and apparently I do have the TH-400 which the pan does look like, and the higher power 4 barrel 350
http://i992.photobucket.com/albums/af41/zadam/003.jpg

It says right here that it's a heavy duty chassis, what wheel bolt pattern is it? I'll bet this is a heavy half:yes:

f16fxr4real
27th-May-2010, 12:29 PM
It says right here that it's a heavy duty chassis, what wheel bolt pattern is it? I'll bet this is a heavy half:yes:

I keep forgetting to pull the hubcaps. Ive been wanting to know if its a 5 or 6 lug, but if its a 5 lug, does that mean it ISN'T a heavy half? I was also worried because according to that sticker in the glove box, it should have the 400 tranny but actually has a 350. Are they the same length? I dont see why my grandfather would have swapped it. Although the guy before him could have. Might be why they added the external tranny cooler after the radiator one.

lugnut
28th-May-2010, 01:22 AM
A quick search of the RPO M40 Turbo-hydramatic seems that chevy used the code for both 350 and the 400. It could have been originally equipped with a 350.

f16fxr4real
30th-May-2010, 11:41 AM
It says right here that it's a heavy duty chassis, what wheel bolt pattern is it? I'll bet this is a heavy half:yes:

Finally got off my lazy butt and pulled the caps.
5 lug, but does that necassarily mean anything.
I didnt find the 350/400 tranny info you did Tim. Where did you find it at? Maybe it meant that had an added external cooler?

Chevy Kid
31st-May-2010, 05:12 AM
My Dad's 77 heavy half had 5 lug wheels, Adam.

Tim

f16fxr4real
31st-May-2010, 12:30 PM
I plan to go get it smogged this week. We'll see what happens. I was just worried about having to get a CAT for this thing.
Smog is a big worry, especially after I saw they can basically make you spend up to 2 grand to get it up to regs

JRouche
31st-May-2010, 10:22 PM
I plan to go get it smogged this week. We'll see what happens. I was just worried about having to get a CAT for this thing.
Smog is a big worry, especially after I saw they can basically make you spend up to 2 grand to get it up to regs

Yeah, the Ca smog checks are a pain. I have a 78 C30 with a 400ci, dual exhaust, no cats. All stock. I was surprised every other year it passed the smog check. Cause really, its a fuel junkie.

Then this last year they got my butt. New laws and the evap system. Which included all of the old dried out fuel vapor recovery hoses. They pull a vacuum on the system now and no way did those hoses pass. I had to run all new hoses, the cost wasnt bad, but the labor was a pain. I had to drop the tank. It was a days worth of work for me, time spent away from working on the Nova.

So I re-hosed the evap system and they gave me my cert. What will they think of next.

They are just trying to run me off the road it seems. Like they want everyone out here in LaLa land to be driving the newest and most expensive cars.

They try to touch my 62 Nova and Ill consider moving from this crazy state. JR

Seattle_Mike
1st-June-2010, 12:03 AM
Yes, a 400 is definitely different length than a 350. The length is 5/8" longer and the mounting pad is about 6" further back than a 350.