Quadrajet Questions
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 2,005
Likes: 0
From: Ridgecrest CA
Quadrajet Questions
At 90k miles, my QJ is leaking pretty bad out the bottom, and now that I put headers on, it is way too lean. My plan is to put a fuel injection system on in about 2-3 years.
Question 1
Being as old as it is, would I be better off rebuilding it before tuning it?
Question 2
If so, can anyone recommend a resource for rebuilding it if it is doable at home? I had little/no problem rebuilding my distributor, replacing all of the suspension, radiator, and power steering system, so I am fairly mechanically inclined.
Question 3
Anyone recommend a resource on tuning the QJ?
Question 1
Being as old as it is, would I be better off rebuilding it before tuning it?
Question 2
If so, can anyone recommend a resource for rebuilding it if it is doable at home? I had little/no problem rebuilding my distributor, replacing all of the suspension, radiator, and power steering system, so I am fairly mechanically inclined.
Question 3
Anyone recommend a resource on tuning the QJ?
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
www.corvettefaq.com is your friend, look up lars paper on the q-jet.
You can rebuild it at home no problem. Get doug roe's book on quadrajets, that'll help A TON. What year is yours? You'll probably be hard put to find new primary metering rods that you want, if it's '75 - '80. If it's pre-75 you'll be in luck because edelbrock still makes the good rods for those. You can get primary jets easily.
You can rebuild it at home no problem. Get doug roe's book on quadrajets, that'll help A TON. What year is yours? You'll probably be hard put to find new primary metering rods that you want, if it's '75 - '80. If it's pre-75 you'll be in luck because edelbrock still makes the good rods for those. You can get primary jets easily.
Veteran
Joined: Oct 2005
Posts: 1,284
Likes: 81
From: Nashville, TN
I just sold mine to a guy for 100. It was a 72 Rochester Q-jet. He only needed a solenoid off it. I had it rebuilt just before I removed it. I am pushing 450 to 500HP now and didn't want to mess with the Q-jet. I am running a Quick Fuel Q-750 now. I you want I can see if he still has it and what he wants or I can just have him PM you.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
peobly the idle stop solenoid. A rebuild is pretty easy, the book Kalway mentioned is a very good one. Once rebuilt and cleaned up the Lars tuning paper will get you up and runnin sweet again
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
If it's any help, Lars gave me some info on Q-jets after fitting Headers. If the stock secondary rods are CH then replacing them with DA rods should get you in the ballpark for the secondary mixture (worked a treat with mine). Haven't a clue on changes to the primary side.
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Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
Originally Posted by UKPaul
If it's any help, Lars gave me some info on Q-jets after fitting Headers. If the stock secondary rods are CH then replacing them with DA rods should get you in the ballpark for the secondary mixture (worked a treat with mine). Haven't a clue on changes to the primary side.
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 2,005
Likes: 0
From: Ridgecrest CA
I pulled the number off it:
17059203
0389 CBB
As I understand, this means that is it a 79 quadrajet for 49 states, off a manual vehicle, though I don't know what the second row of numbers is. As a side note, it has another sticker on it that states it was rebuilt by Holley, with these numbers:
7160AA
1403-8506B0
I think it must have been modified (possilby during the rebuild), because according to Lar's paper on tuning, this should not have the electric choke that it has.
Looking at rebuild kits, they have 3 different ones for different edelbrock quadrajets. Is there a simple way to figure out which one I need?
Also, it seems that I cannot buy the proper primary rods for this carb? So am I stuck with either using the wrong rods or buying an older carb?
17059203
0389 CBB
As I understand, this means that is it a 79 quadrajet for 49 states, off a manual vehicle, though I don't know what the second row of numbers is. As a side note, it has another sticker on it that states it was rebuilt by Holley, with these numbers:
7160AA
1403-8506B0
I think it must have been modified (possilby during the rebuild), because according to Lar's paper on tuning, this should not have the electric choke that it has.
Looking at rebuild kits, they have 3 different ones for different edelbrock quadrajets. Is there a simple way to figure out which one I need?
Also, it seems that I cannot buy the proper primary rods for this carb? So am I stuck with either using the wrong rods or buying an older carb?
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by Berserker78
I pulled the number off it:
17059203
0389 CBB
As I understand, this means that is it a 79 quadrajet for 49 states, off a manual vehicle, though I don't know what the second row of numbers is. As a side note, it has another sticker on it that states it was rebuilt by Holley, with these numbers:
7160AA
1403-8506B0
I think it must have been modified (possilby during the rebuild), because according to Lar's paper on tuning, this should not have the electric choke that it has.
Looking at rebuild kits, they have 3 different ones for different edelbrock quadrajets. Is there a simple way to figure out which one I need?
Also, it seems that I cannot buy the proper primary rods for this carb? So am I stuck with either using the wrong rods or buying an older carb?
17059203
0389 CBB
As I understand, this means that is it a 79 quadrajet for 49 states, off a manual vehicle, though I don't know what the second row of numbers is. As a side note, it has another sticker on it that states it was rebuilt by Holley, with these numbers:
7160AA
1403-8506B0
I think it must have been modified (possilby during the rebuild), because according to Lar's paper on tuning, this should not have the electric choke that it has.
Looking at rebuild kits, they have 3 different ones for different edelbrock quadrajets. Is there a simple way to figure out which one I need?
Also, it seems that I cannot buy the proper primary rods for this carb? So am I stuck with either using the wrong rods or buying an older carb?
Go on ebay motors NOW and search for "metering rods" JJ's smoking deal has a few left. Any of the k or p primary metering rods will work. Jets are easy to get. The rods are only $5 a pair. GO!
The edelbrock kit you want will be for a 1903 or 1904 M4M q-jet.
Veteran
Joined: Oct 2005
Posts: 1,284
Likes: 81
From: Nashville, TN
Originally Posted by Berserker78
I'm interested. Which solonoid was it?
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by King Lear
No idea, I dont know my ahole from a whole in the ground when it comes to Q-jets. I prefer the good old double pumper! Which is why I no longer have a Q-jet and my old Jeep 360 had one, what a pain in my !!! My father in law has one that is leaking gas out the top of his 1980 vette. We are getting ready to do his intake and carb, I can check if you are interested in buying his. I think it is in need of a top gasket on the carb as only fuel is gumming up around the top.
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 2,005
Likes: 0
From: Ridgecrest CA
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by Berserker78
Yup.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by King Lear
That may be true, but you cant polish a turd. After the 3 minutes you still have a Q-jet pice of junk made by Rochester.
Show me another carburetor that lasts 10+ years without NEEDING a rebuild.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Originally Posted by Bob Onit
Dont waste your time Kal
Some like the QJ some dont.....
Some like the QJ some dont.....
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by King Lear
That may be true, but you cant polish a turd. After the 3 minutes you still have a Q-jet pice of junk made by Rochester.
Originally Posted by King Lear
I dont know my ahole from a whole in the ground when it comes to Q-jets.
I would love to see you meet Lars face to face and let him show you how to make your bastardized Corvette run properly with a Qjet
ps: Nice hole in your hood
