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Alfetta Smog Parts - What do these do?

2K views 12 replies 4 participants last post by  velocedoc 
#1 ·
In the process of updating a 76 Alfetta. Orig California car, now in Oregon (no smog checks in my county!). I'm taking everything out of the engine bay for a re-paint, and am only putting back the stuff needed. So... this stuff?
Previous Owner cut a lot of wires to these components, but I still see air hoses running everywhere. My questions are these -
1) what are these things? I've numbered them for your viewing and responding convenience...
2) can I just remove some/all of them and plug the places where the hoses go into the engine?
3) will the engine run just as good or better without all of this?

This car isn't going back to California, so not worried about smog compliance.
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#2 ·
I will take a stab at this as it has been years since I messed with this stuff. So much of these smog parts were tossed in the trash years ago it is hard to remember where it all connected. I will try to help. It was a complex system that worked inspite of its complexity.

There were two vacuum connectors on the bottom of the air filter box, a connection on the front of the intake manifold, two hoses to the vapor oil recovery unit, a relay for the twin points distributor that used vacuum to switch points, air pump and filter on the exhaust side that fed air into the exhaust manifold, and a hot air feed off the exhaust to the intake side of the air filter inlet, and a vacuum feed for the air flapper cold air bypass.

When cold the air flapper on the filter box would close and draw hot air from the exhaust manifold. As the car warmed up the flapper would open drawing in cold air. The distributor would be retarded to cut emissions until the car accellerated. The air pump would be adding fresh air downstream to burn off unburnt fuel before it reached the catalytic converter. There was a sensor in the exhaust just ahead of the catalytic to warn if it was to rich and over heating kicking a over heat light on the console.

The one marked as #4 is most likely a purge valve for the fuel tank vapor tank. It should connect to somewhere on the intake side and one side to the firewall plastic hose sticking out. It is activated in the crank position of the start cycle. The other it could have been is for the cold air flapper on the front of the air filter box?

The other part looks like a replacement for the original one that probably snapped off the plastic tip. This is part of the distributor retard for when the car is at idle. The distributor had two sets of points. When the car was at idle the retard points would be activated. When the car pulls a vacuum on acceleration, the 2nd set of advance points would kick in. This valve was the actuator for this action.

Yes, you can leave all of that out. Just put it in a box for safekeeping as this stuff is becoming unobtanium. Someone will want to make a show car and need this stuff to make it complete.
 
#3 ·
Christopher... AWESOME! Thanks much for the reply! Was thinking the same but you confirmed. Agree that this stuff is probably super-rare; so many of these were tossed in the trash, I’m sure. Out of my car they come!
 
#4 ·
Glad I can help. The cars were so smogged in 75-76 that they were dogs on performance. In 78-79 the cars improved performance with some changes in cams and exhaust manifold changes.
Be sure you plug off the port on the front of the intake manifold or #1 piston will run hot with that extra air. The same with the hose on the firewall that leads to the vapor canister. Find a late model set of Alfetta headers without the air ports or use 1/8" pipe plugs to fill the holes with anti-seize compound. If you have the air flapper on the front of the filter box, you can change it out for an earlier one or just disconnect the vacuum lines.
Reset your cams to a 74 model year or get some high-performance cams.

I just remembered that one of the two ports on the bottom of the air filter box let to the flapper valve, but not sure where the other one went. Maybe to the purge valve?

On the distributor use the straight points. That is the advanced set or get a new distributor with electronic points.

Stupid California still requires all of this stuff to be connected on a 76 & later car. The parts are getting harder to find for a 40+-year-old car. Therefore, their intent is to get these less compliant cars off the road. They even check the car for the vapor recovery for a sealed system and pull a suction on the gas cap hoping to trap every little bit of fumes they can. There are so few cars that are 40+ years old on the road it really doesn't amount to a hill of beans as they say. Another topic for the BB!
 
#5 ·
All good advice, to be sure! Planning on newer cams and electronic distributor and euro headers. Will do something with the stock air box. The bb articles imply that the plenums in the stock box are best, but it would sure be nice to have something less... gargantuan...

thanks again!
 
#6 ·
One of the modifications that I heard about years ago, was to open the back of the air box so it pulls air from both ends. I have no experience with this so it is just 'hear-say'. Maybe someone else can chime in here.
My close friend, Slowcreek has an Alfetta that he has fixed up and goes great. You might want to reach out to hime.
 
#7 ·
As a native of this beautiful but politically crazy state of California, I will once again have to pass smog April next year for my 1976 Alfetta GT. It will easily pass after installing a new T.A. and a Cal Cat. last year. No other state requires smog tests for 43 y.o. cars...It's just part of the price for living here........
 
#10 ·
wanna drag this back to my orig question... started taking all this stuff off today. There was a wire from #2 in the pic above to the fuel cutoff solenoid! Does that make sense? I’m not making claims that any wiring on this car was right, and it ran VERY poorly when I test drove it... but was surprised to find that wire attached that way. Thanks for help.
 
#11 ·
From what I can recall the cut off solenoid should only have one wire. One from under the pump that connects to the cut off switch. The other wire goes to 12v+. is there a switch on the dash or button? Sometimes the cold start is set to rich and it floods the car, so we used to put an interrupter switch in line to cut off the cold start.
See if anyone has a copy of the Alfetta wiring diagram from Papajam. that will help you sort out the wiring.
 
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