Quadrajet Help...please
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
Quadrajet Help...please
I am doing a major tune up on my buddy's '70 454 matching numbers coupe....shielded wires are old and brittle, old plugs, points and a chinese made coils. Replaced all of the above. Car has a reman carb on it now and is running extremely rich.....like clouds of black smoke when you goose it.
So he buys a Champion Brand reman carb from AutoZone......same thing.....and the car actually runs woose than I before started
dumping alot of gas into the intake..
Sooooo I put my LARS rebuilt Q-Jet off my '72 350 Vert and the car runs PERFECT.....Thank you Lars
I just don't get it ...how hard is it to rebuild a carb...especially if you are a company that does it everyday...oh yeah these carbs are supposed to be tested...right
Is Lars still on a break from building carbs????
If so, anyone know where he can get a good carb???
Mark
So he buys a Champion Brand reman carb from AutoZone......same thing.....and the car actually runs woose than I before started
dumping alot of gas into the intake..Sooooo I put my LARS rebuilt Q-Jet off my '72 350 Vert and the car runs PERFECT.....Thank you Lars
I just don't get it ...how hard is it to rebuild a carb...especially if you are a company that does it everyday...oh yeah these carbs are supposed to be tested...right
Is Lars still on a break from building carbs????
If so, anyone know where he can get a good carb???
Mark
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Not that big a deal. Probably got bounced around a lot in shipping/ handling and the float is stuck or jammed or out of whack.
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by noonie
Not that big a deal. Probably got bounced around a lot in shipping/ handling and the float is stuck or jammed or out of whack.
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Mis- matched parts ,sloppy bushings re-drilled, oversized vacuum ports.... total garbage
Never even bothered to take the air horn off.... just took it back and got my refund
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
Originally Posted by noonie
Not that big a deal. Probably got bounced around a lot in shipping/ handling and the float is stuck or jammed or out of whack.
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Take the carb apart and check it out. No replacements are just bolt on. Did the idle adj screws do anything?
Oddly enough I checked the ORIGINAL application (researching the numbers stamped on the side)and this carb was originally for a 70 GMC/Chevy California truck with a 350.
And this what they supply for ALL GM V8s with a 4 BL ,reguardless if it a Nova with a 350 or a Goat with a 455, 454 Vette, 454 SS Chevelle etc.
Mark
Last edited by mbeeman350; Jul 26, 2006 at 12:19 AM.
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by mbeeman350
I took the carb apart before the instal...no numbers on the rods or Jets....thought that was strange float was good Idle screws had little effect since there is so much gas being dumped into the intake.
Oddly enough I checked the ORIGINAL application (researching the numbers stamped on the side)and this carb was originally for a 70 GMC/Chevy California truck with a 350.
And this what they supply for ALL GM V8s with a 4 BL ,reguardless if it a Nova with a 350 or a Goat with a 455, 454 Vette, $54 Chevelle etc.
Mark
Oddly enough I checked the ORIGINAL application (researching the numbers stamped on the side)and this carb was originally for a 70 GMC/Chevy California truck with a 350.
And this what they supply for ALL GM V8s with a 4 BL ,reguardless if it a Nova with a 350 or a Goat with a 455, 454 Vette, $54 Chevelle etc.
Mark
Also if you have some spare jets and rods try leaning it out.. It might work
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
Originally Posted by Bob Onit
Does it look like a truck carb?
Also if you have some spare jets and rods try leaning it out.. It might work
Also if you have some spare jets and rods try leaning it out.. It might work
The new carb matches the POS reman we just took off.
Don't know what the original 70 BB 454 4 speed carb looks like...
Burning Brakes
Joined: Sep 2005
Posts: 755
Likes: 1
From: Hobart Tasmania
I had a carby professionally reconditioned and the thing would not stop flooding. Turns out when it was originally shipped dry, a small hole must have worn in the brass float. When fitted the float filled up with fuel causing it to sink and flood the carby. She runs like a dream now.
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Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Originally Posted by mbeeman350
I just don't get it ...how hard is it to rebuild a carb...especially if you are a company that does it everyday...oh yeah these carbs are supposed to be tested...right
BigBlockk
Later.....
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
Originally Posted by BigBlockk
It is easy to rebuild a carburetor but if the calibration is wrong it's wrong. Rebuilding the carburetor is not going to change that because there is a difference between rebuilding and tuning. Rebuilding is simply cleaning and replacing worn parts. You can not tune a carburetor with a rebuild kit.
BigBlockk
Later.....
BigBlockk
Later.....
Going to return the reman carb to AZ
In the meantime we found a carb rebuilder in St Pete to build a carb to factory specs for this car. He had all the specs, to be sure we gave them to him again, the original rod and jet sizes, spring etc.. for this car...
Well see....carb will be here Thursday...will post results...
Mark
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Originally Posted by mbeeman350
Thanks BB..that's it exactly.....I learned a good lesson on rebult carbs. The builders try to cover too many apllications with just one carb.
Going to return the reman carb to AZ
In the meantime we found a carb rebuilder in St Pete to build a carb to factory specs for this car. He had all the specs, to be sure we gave them to him again, the original rod and jet sizes, spring etc.. for this car...
Well see....carb will be here Thursday...will post results...
Mark
Going to return the reman carb to AZ
In the meantime we found a carb rebuilder in St Pete to build a carb to factory specs for this car. He had all the specs, to be sure we gave them to him again, the original rod and jet sizes, spring etc.. for this car...
Well see....carb will be here Thursday...will post results...
Mark
WHEN YOU HAVE A CARBURETOR TO REBUILD, GET THE REBUILD KIT (ECHLIN), JET/ROD COMBO FOR YOUR CARBURETOR, NEW FLOAT AND NEW CHOKE PULLOFF AND TAKE ALL OF IT TO YOUR RE BUILDER. MAKE SURE THEY UNDERSTAND THAT THE SETUP SHOULD BE IN THE CARBURETOR WHEN YOU COME BACK TO PICK IT UP.
I an not shouting I just want everyone to take note.
Mark, this is a very good idea.
BigBlockk
Later.....
Last edited by BigBlockk; Jul 26, 2006 at 03:30 PM.
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
I have built and tuned a lot of Holleys over the years but ran away from the Q-Jets. Now after doing some research and having Lars do my mine, as well as reading Lars Paper. I would tackle the next one.
In this case its a buddys car, parked in my Vette's space, in my garage...he doesnt want to wait on ordering parts, just got the car and wants to drive it....right now!!!
Otherwise I would have gone throug his old carb, ordered parts etc. This is an intack very nice BB coupe, 70, EXCEPT the alternator and carb!!!
Mark
In this case its a buddys car, parked in my Vette's space, in my garage...he doesnt want to wait on ordering parts, just got the car and wants to drive it....right now!!!
Otherwise I would have gone throug his old carb, ordered parts etc. This is an intack very nice BB coupe, 70, EXCEPT the alternator and carb!!!
Mark
Last edited by mbeeman350; Jul 26, 2006 at 10:24 PM.
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by mbeeman350
Not sure what a truck carb looks like!!!
Truck QJ's look a little different from the top
Heres a truck QJ
And heres a passenger car QJ
Notice the difference in the position where the fuel is introduced
Hope this helps
Last edited by Bob Onit; Jul 26, 2006 at 03:45 PM.
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by corvette_maniac
Everyone knows that the bottom one is an 4MV. You can always tell them by the blue needle nose pliers.
The top is a 1978 truck carb and the bottom is a 1973 4MV
Watch out Kal, or I'll knock you off your tricycle
ps: I only have 2 hands, what else could I have used to hold the choke open for the pic.?
Nope, not that, the bench was too low
Last edited by Bob Onit; Jul 26, 2006 at 09:42 PM.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by Bob Onit
Exactly
The top is a 1978 truck carb and the bottom is a 1973 4MV
Watch out Kal, or I'll knock you off your tricycle
ps: I only have 2 hands, what else could I have used to hold the choke open for the pic.?
Nope, not that, the bench was too low
The top is a 1978 truck carb and the bottom is a 1973 4MV
Watch out Kal, or I'll knock you off your tricycle
ps: I only have 2 hands, what else could I have used to hold the choke open for the pic.?
Nope, not that, the bench was too low
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by Kalway
The q-jet design changed quite a bit around '76, I believe. That was the introduction of the 795cfm M4M q-jet (17xxxxxx). Doesn't mean it's a truck carb, it's just a different model.
Im just going by what a builder told me
Ill plow through Doug Roe's book when I get a chance