quadrajet 1978 -1979

[wayne lawrence]

I have a 1978 engine and carb in my 76 Birchaven. The carb has a rebuilt sticker on it.
My secondary air valve only opens about 1/3 (hard stop) of the way.All the adjustments are close, but does any one know how far the air
valve is supposed to open?
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[john r. lebetski]

All the way, conditions permitting. Reving it in neutral will not meet those load conditions. The vacuum dashpot, wind up spring and downward air
flow are a balancing act.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[wayne lawrence]

Thanks John,
That,s what I thought. The vacuum rod hits the end of the slot on the air valve lever @ about 1/3 of the way open.
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[6cuda61]

Is that when driving and going to WOT? Or just trying to open it with your finger or at idle?

BTW there are a couple really good QJet videos on you tube about proper tuning and setup.....i forget what the guys name is, he swears alot but he
know his stuff and talks about all the things people do to the secondary air flaps thinking it makes the QJ work better when it doesn't.

> Thanks John,
> That,s what I thought. The vacuum rod hits the end of the slot on the air valve lever @ about 1/3 of the way open.

--
Rich Mondor,

Brockville, ON

77 Hughes 2600

 

[john r. lebetski]

If OFF it won’t fully open by hand with choke open, something is wrong. I’ve seen them where all the parts were there but assembled incorrectly.
We might need a picture.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[LarryW]

When the Secondarys on my coach would not open all of the way I discovered that the arm on the gas pedal had bent. Maybe that happened to you also?
Just grab the gas pedal and pull hard on it and bend it back up to where it belongs. Simple, the throttle pedal was simply hitting the floor before
the throttle plates were fully open. A simple fix.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[wayne lawrence]

The rod from air valve and the pull off diaphragm was backwards . installed it correctly and now they open all the way.

Does the secondary lock out have a lever to move it out of lockout when the choke is open or does it depend on gravity to unlock it
when the choke opens?
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[wayne lawrence]

The rod from air valve and the pull off diaphragm was backwards . installed it correctly and now they open all the way.

Does the secondary lock out have a lever to move it out of lockout when the choke is open or does it depend on gravity to unlock it
when the choke opens?
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence

 

[john r. lebetski]

You should be able to play with choke by hand and see how it opens the lock tang. Basically gravity closes the lock and the mechanism moves it open.
So I guessed right on that secondary air valve linkage. I had bought a $750 winter beater a 77 Monte Carlo with 350/4 in Vegas and drove it back. It
had same misassembled issue. Easy fix no cost.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[john r. lebetski]

Also in addition to what Larry said, you can get more throttle pull by slightly sliding rearward and slightly bending rearward the throttle cable
bracket at left rear of carb. Engine OFF Hold the air valve open and operate pedal with your left foot as you shine a light down secondaries. The
lower throttle plates should go vertical.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[johnny]

Someone - Lenzi maybe? - removes the secondary lockout on his rebuilds. He says it iosn't really necessary in this service and as you're seeing can
create troubles.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[powwerjon]

Not Lenzi, Dick Patterson does the rebuilds on the carbs. They are like brand new and have the correct parts. The real problem is whether your carb is a actual GMC carb and the numbers are correct.

http://www.springfield-ignition.com/gmc-motorhome/carburation/

JR Wright

>
> Someone - Lenzi maybe? - removes the secondary lockout on his rebuilds. He says it iosn't really necessary in this service and as you're seeing can
> create troubles.
>
> --johnny
> --
> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> I forgive them all, save those who hurt the dogs. They must answer to me in hell
>
>
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[wayne lawrence]

As usual you guys have saved me a lot of time and I really appreciate it.

THANK YOU
--
Wayne Lawrence
76 Birchaven
Bellflower CA
w.lawrence