deisenreich

I live in California and just bought an 80 vette from out of state. I am trying to get the car ready for its first CA smog test. The previous owner disconnected some of the vacuum lines from the carb and the egr valve. Is there any place that i can find pictures or diagrams of whats supposed to go where so that i can reconnect all the smog stuff properly? Thanks. :confused:

BSeery

Some times the under-hood sticker shows a vacuum diagram.

A Haynes manual or AIM manual may have them as well.
I would send you pictures of my engine, but most of that stuff is now gone.

You should have an AIR pump, with 2 large hoses going off to check valves mounted to the pipes coming from the exhaust manifolds.
An EGR valve, and I think that is connected to vacuum through a TVS (thermal vacuum switch - or something like that), same for a vacuum line running to the the AIR pump.
There should be a vacuum line going to the charcoal canister and a large vent line from the carburetor to the canister as well.

Hopefully someone has a full vacuum diagram, but that at least lets you know what was there.

For some really crappy pictures of my old engine Click HERE

deisenreich

Thanks for the info. I took a look at your pictures and i was able to determine that the air pump is gone, egr removed and some vacuum lines plugged. I will have to try to get an air pump assembly from somewhere or else figure another way to get clean enough to pass smog without the air pump. :(

BSeery

If they don't do an underhood check of what you have installed, you should be able to pass a simple tailpipe 'sniffer' test.

Just takes a good tuned carb, right timing, good plugs, wires and cap and rotor. My 1978 C-10 truck with a 350 engine passes with the exact same numbers that my 1980 C3 with a ZZ4 and electronic fuel injection did. Just a matter of tuning.

hunt4cleanair

Hate to say it but I believe the 305 LG4 was the only Corvette motor emission certified for CA in 1980. The others were the L48 and L82 and L82 was out of the picture in terms of emission certification.

So having said that...the emission sticker is the certification for the vehicle and will have the hose diagram printed on it. Dr Rebuild does the nicest job of diagrams and replacement hose kits. The 1980 shop manual will list the specs of tuning the motor plus offer insight into the operation of the various emission control systems equipped on the 1980 Corvette. Helms (helmsinc) sells the manuals for all GM cars. Another site is the factoryautomanuals.com. If you have patience, you can pick up manuals and pumps on eBay...but then you have to worry about the extent to which they still operate.

Sounds like in addition to the pump and pipes, your mounting hardware is missing as well. Another big ticket item is the catalytic converter and exhaust system. If Bubba removed all the smog, probably removed exhaust restrictions as well. All this equipment is what brought Corvettes into compliance and CA had the most stringent laws in the country...and may still have the same.

You may also wish to check and see if Bubba removed the charcoal cannister vapor emission control hardware. Hoses would lead to it...it's located under the driver's side fender and then hosed back to the fuel tank. Check the top of the fuel tank for hoses plugged that lead off to the driver's side.

Once you've assessed these other systems...let us know what you find. Hope this help...feel free to drop me a note if you need additional information.

GaryS

If you must have the AIR air pump, Bill Hodel, 330-832-0871, is the man to see. Not cheap but good. If you don't want or need a numbers matching AIR system, I would bet that he can hook you up with a setup much cheaper than us numbers-needing addicts. Btw, get yourself an Assembly Instruction Manual (AIM) and it will show how all of your vacuum hoses, EGR, and smog stuff is hooked up. Well worth the few bucks.

In addition, prior to your smog test, change your oil and filter. Helps reduce emissions for a very short time.
Gary

DaveL82

Not sure if all 80's had the pump. Usually it was on the L82 only for the 49 states nd then on the 305 sold in CA. If yours is an 80 49 state motor it will not have the pump.

Not sure how the rules are written for CA. You may find it will pass without the air pump if allowed.

hunt4cleanair

Quote:

Not sure if all 80's had the pump.

All 80's (305, 350's) had the 7817872 pump used from 1978 through 1980

BSeery

The 305 motor was the only Corvette engine legal for sale in California in 1980. You can however bring in an out of state vehicle and get it to pass emissions.

I am sure there are plenty of 1980 Corvettes with a 350 in them that are passing emissions.

deisenreich

THanks for all the info guys. The car still has the cat. converter and the charcoal canister is present but unhooked. I will pick up a shop manual and try to get an air pump + assembly/brackets on ebay or elsewhere. Does anyone know what the part number would be for the exhaust manifolds, and where the number would be? I need to figure out if the manifolds have been replaced, since i would have no place to hook up the air hoses to the manifold if its been replaced with a non compliant one.
Thanks again for all the advice. This is my first vette, and i have waited so long to get one it would be a shame not to be able to drive it. :crazy:

deisenreich

Another forum member located near me in CA has the air system from a 75 vette, will it fit in mine?

hunt4cleanair

Pumps are calibrated to emit so many ppm of oxygen. In 75, the cat converter was introduced and GM was probably still tinkering withe the mix. Also one of those years between 74-76, used a single pipe instead of 4 per side as in 80. Also as I recall, the emissions standards tightened in 77...so 75 would not help you meet requirements set for an 80 car.

Paul L

The exhaust manifolds for the 1980 LG4 305 were tubular stainless steel: 14037671-W (left) and 14037672-W (right).

DaveL82

Just buy the rams horn exhaust manifolds with the 4 air pump inlets. These are not expensive and bought mine new from Contempory Corvette. After years of header leaks this was the way to go. Plus it hides my ZZ4 sleeper engine real nice.

On the 80, my L82 air pump is on top of the motor so any bracket set should work. Just order a replacment pump for an 80 (not too expensive these days). You also need the pulley for the water pump.

Also replace the converter as a baseline.

Dave

marshrat99

Here's a diagram of what was on my 79 L82. Hope this helps.
http://www.docrebuild.com/dr-r-web/3750367.HTML

:cheers:

deisenreich

Thanks again for the help. A forum member has the system from an 81 available, will this unit work? I know 81 is computer controlled, but i am not sure if this affect the air pump assembly. Thanks again,
Dave

BSeery

It will work just fine. In 1981 the computer only controlled carb mixture, timing and torque convertor lockup. The emissions system was "stand alone" and did not connect with the computer.