One more quick Quadrajet question..sorry
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
One more quick Quadrajet question..sorry
I have just finished a rebuild on a 73 core I picked up.
My car is a 73 L48 stock except for Edelbrock Performer intake.
I have set it up with 73 main jets/44 pri rods and DA sec rods which is what the specs call for.
Running VERY rich at idle but ONLY on the passenger side...I can see the smoke while at idle and while revving it when it is sitting still.
Adjusting the mixture screw on the pass side has NO effect at all... adjusting the mixture screw on the drivers side does effect things as it should..(This is what has me puzzled)
Anybody have any idea why the mixture screw has zero effect on the pass side?
I have 2 other Qjets that run great on this car but they are setup a tiny bit different than the one I am working on. 73 main jet/43 pri rods and DR sec rods.
So ....I have 2 questions.. Why does the Idle screw on the pass side have no effect whatsoever and second,can having a 44 main rod rather than the 43 (which runs great on my other carbs) make any difference at all?
Thanks once again....
My car is a 73 L48 stock except for Edelbrock Performer intake.
I have set it up with 73 main jets/44 pri rods and DA sec rods which is what the specs call for.
Running VERY rich at idle but ONLY on the passenger side...I can see the smoke while at idle and while revving it when it is sitting still.
Adjusting the mixture screw on the pass side has NO effect at all... adjusting the mixture screw on the drivers side does effect things as it should..(This is what has me puzzled)
Anybody have any idea why the mixture screw has zero effect on the pass side?
I have 2 other Qjets that run great on this car but they are setup a tiny bit different than the one I am working on. 73 main jet/43 pri rods and DR sec rods.
So ....I have 2 questions.. Why does the Idle screw on the pass side have no effect whatsoever and second,can having a 44 main rod rather than the 43 (which runs great on my other carbs) make any difference at all?
Thanks once again....
Racer
Joined: Apr 2006
Posts: 477
Likes: 43
From: Millbrae California
check to see if the idle tube (jet) in the fuel bowl is open on both sides, one side most likely has a piece of debris in it. the restriction is 0.038" on a 7043202 q-jet and the restriction/jet is about 1 1/2" down the idle tube measured from the gasket surface of the bowl. we use custom made longer than normal reams (2") to check or resize idle tubes/jets without having to remove them. new tubes are avalible but they do not fit as well as the OEM tubes and some tuners use replacement threaded idle tubes. you could use a vacuum pump to be sure both tubes are open for fuel flow
my data base shows us using a #74 jet for our fuel in california so the 74 jet should be fine with the rod you are using
henry @ oles carb
my data base shows us using a #74 jet for our fuel in california so the 74 jet should be fine with the rod you are using
henry @ oles carb
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by olescarb
check to see if the idle tube (jet) in the fuel bowl is open on both sides,
Time for some research
Thanks
Racer
Joined: Apr 2006
Posts: 477
Likes: 43
From: Millbrae California
the idle tube or "idle jet" is the supply source of the fuel for the idle system. it is a 1 1/2" long brass tube pressed into the fuel bowl near the top screws that are under the choke valve. see pages 238 thru 240 in the doug roe rochester carb book.
henry @ oles carb
henry @ oles carb
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by olescarb
the idle tube or "idle jet" is the supply source of the fuel for the idle system. it is a 1 1/2" long brass tube pressed into the fuel bowl near the top screws that are under the choke valve. see pages 238 thru 240 in the doug roe rochester carb book.
henry @ oles carb
henry @ oles carb
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
I got the pics Mr Ols ...thanks!
Ok ... another question about gaskets
Here are 2 pics of the air horn gaskets
The one WITHOUT the cut out is the original gasket
The one WITH the cut out is what comes in the GP Sorensen kits I bought
Is it OK to use the gasket with the cut out on a 73 #7043202 ?
Thanks for all your help
Ok ... another question about gaskets
Here are 2 pics of the air horn gaskets
The one WITHOUT the cut out is the original gasket
The one WITH the cut out is what comes in the GP Sorensen kits I bought
Is it OK to use the gasket with the cut out on a 73 #7043202 ?
Thanks for all your help
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Racer
Joined: Apr 2006
Posts: 477
Likes: 43
From: Millbrae California
the cutout gasket is the one to use, the cut out is where the air to the idle air bypass comes from (extra air that does not go past the throttle valves) the other gasket ( non- cut out) is for a different q-jet (earlier year or non chevy).
henry @ oles carb
henry @ oles carb
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by olescarb
the cutout gasket is the one to use, the cut out is where the air to the idle air bypass comes from (extra air that does not go past the throttle valves) the other gasket ( non- cut out) is for a different q-jet (earlier year or non chevy).
henry @ oles carb
henry @ oles carb
Thanks Ols
Kal? Did you see the pic of the dolled up QJ mounted in a previous post?
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by Bob Onit
Geeze........No wonder things arent running right.
Thanks Ols
Kal? Did you see the pic of the dolled up QJ mounted in a previous post?
Thanks Ols
Kal? Did you see the pic of the dolled up QJ mounted in a previous post?
Burning Brakes
Joined: Feb 2005
Posts: 977
Likes: 1
From: wash. dc
Originally Posted by Kalway
I think we should have a jeopardy match between olescarb, lars, and bigblockk and all of the topics will be based on parts of the q-jet. :
that would be a battle of the brainiacs
Racer
Joined: Apr 2006
Posts: 477
Likes: 43
From: Millbrae California
thanks for the nice comments but i don't think I or any one person knows it all. i may have been working with fuel systems since i was 4 years old but i still learn something new everyday. my job(s) allow me to consult with some of the big dogs in the ignition, fuel injection and carburetor fields and how modern gasoline effects thier calabrations, all of this just points out that there is still a lot more for me to learn!
henry @ oles carb
henry @ oles carb
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Originally Posted by Bob Onit
Is this it?
On the passenger side it is at about 2 o'clock.
I think this is why Lars recommends the Echlin kits.
I'm surprised the engine idled at all.
BigBlockk
Later.....
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Bah......... screwed around with it for hours today...
It's not getting any fuel...
I have many floats and seats/needles
For some reason I cannot get fuel to the float bowl
I CAN NOT get the wire (hanger) to stay on the float...
Too many hours with negative results
It's not getting any fuel...
I have many floats and seats/needles
For some reason I cannot get fuel to the float bowl
I CAN NOT get the wire (hanger) to stay on the float...
Too many hours with negative results
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by BigBlockk
Now, you do know there are long fulcrum and short fulcrum floats don't you? You can not mix and match them.
BigBlockk
Later.....
BigBlockk
Later.....
I have both....Ill try later today when whats left of my mind is fresh again