QuadraJet DialIn/Tune
Thread Starter
Racer
Joined: Apr 2007
Posts: 278
Likes: 17
From: Caledonia WI
QuadraJet DialIn/Tune
I know this is the C3 forum, but I figure you guys have much more carb knowledge than the C4 forum.
I have a Q-Jet on my 84. After much troubleshooting, including diassembly of the carb, it turns out my problem was a badly failed fuel pressure regulator.
Now I have it running, responding to the throttle well, not dripping gas onto the manifold and all. I have 2 problems, though.
(If anyone wants to come to the Racine area to help me out, there is beer in it for them
)
1. Idle. I turned the stop screw on the throttle linkage up enough to keep it running at idle, but I am pretty certain that this is the WRONG way to do it, especially if the sound is any indication.
2. It is running REALLY rich, based on the exhaust smell.
I am getting a carb baptism by fire. So far I am learning a lot. Based on some of the stuff I saw, I am not sure if this carb is damaged otherwise. (Front bolts appear to have ground/scraped away part of the aluminum body.)
Direct help, "go to this website", here is PDF, etc would be HUGELY appreciated.
I have a Q-Jet on my 84. After much troubleshooting, including diassembly of the carb, it turns out my problem was a badly failed fuel pressure regulator.
Now I have it running, responding to the throttle well, not dripping gas onto the manifold and all. I have 2 problems, though.
(If anyone wants to come to the Racine area to help me out, there is beer in it for them
)1. Idle. I turned the stop screw on the throttle linkage up enough to keep it running at idle, but I am pretty certain that this is the WRONG way to do it, especially if the sound is any indication.
2. It is running REALLY rich, based on the exhaust smell.
I am getting a carb baptism by fire. So far I am learning a lot. Based on some of the stuff I saw, I am not sure if this carb is damaged otherwise. (Front bolts appear to have ground/scraped away part of the aluminum body.)
Direct help, "go to this website", here is PDF, etc would be HUGELY appreciated.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I know this is the C3 forum, but I figure you guys have much more carb knowledge than the C4 forum.
I have a Q-Jet on my 84. After much troubleshooting, including diassembly of the carb, it turns out my problem was a badly failed fuel pressure regulator.
Now I have it running, responding to the throttle well, not dripping gas onto the manifold and all. I have 2 problems, though.
(If anyone wants to come to the Racine area to help me out, there is beer in it for them )
1. Idle. I turned the stop screw on the throttle linkage up enough to keep it running at idle, but I am pretty certain that this is the WRONG way to do it, especially if the sound is any indication.
2. It is running REALLY rich, based on the exhaust smell.
I am getting a carb baptism by fire. So far I am learning a lot. Based on some of the stuff I saw, I am not sure if this carb is damaged otherwise. (Front bolts appear to have ground/scraped away part of the aluminum body.)
Direct help, "go to this website", here is PDF, etc would be HUGELY appreciated.
I have a Q-Jet on my 84. After much troubleshooting, including diassembly of the carb, it turns out my problem was a badly failed fuel pressure regulator.
Now I have it running, responding to the throttle well, not dripping gas onto the manifold and all. I have 2 problems, though.
(If anyone wants to come to the Racine area to help me out, there is beer in it for them
)1. Idle. I turned the stop screw on the throttle linkage up enough to keep it running at idle, but I am pretty certain that this is the WRONG way to do it, especially if the sound is any indication.
2. It is running REALLY rich, based on the exhaust smell.
I am getting a carb baptism by fire. So far I am learning a lot. Based on some of the stuff I saw, I am not sure if this carb is damaged otherwise. (Front bolts appear to have ground/scraped away part of the aluminum body.)
Direct help, "go to this website", here is PDF, etc would be HUGELY appreciated.
Look up info on Power valve in recommendations
I love the rochester
problem is getting the jets/needles/PV springs/hangers
There is info in books.
Can not believe you have not found info on the web.
Why did you go carb?
is the engine built?
What original application was the carb for?
Buy a book
Instructor
Joined: Apr 2009
Posts: 219
Likes: 0
From: Missouri
Nothing wrong with a Q-jet, once they are dialed in.
It has been 20years since I messed with them but here are a couple helpful links to get you started.
http://www.carburetor.ca/carbs/tech/...jet-index.html
http://www.themotorbookstore.com/howtoreandmo1.html
It has been 20years since I messed with them but here are a couple helpful links to get you started.
http://www.carburetor.ca/carbs/tech/...jet-index.html
http://www.themotorbookstore.com/howtoreandmo1.html
Thread Starter
Racer
Joined: Apr 2007
Posts: 278
Likes: 17
From: Caledonia WI
It was rebuilt, supposedly just a standard re build, though.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
How about the ECM and Distributor?
No smog req'ts?
Good luck.
Roch is a good carb. After you glue the plugs and find the right parts.
Thread Starter
Racer
Joined: Apr 2007
Posts: 278
Likes: 17
From: Caledonia WI
I am fairly certain that the distributor is replaced.
No smog where I am going to register it.
The plugs are glued. It is back together and it runs, albeit rich, but does not idle. I need to get it all dialed in. Not pissing gas anymore, either.
Melting Slicks
Joined: Jul 2006
Posts: 2,292
Likes: 494
From: Salmon Arm, BC
Here is a great site for Qjet info and help....Cliff is a great guy and is glad to help diagnose problems......hes got parts too
http://www.cliffshighperformance.com...machinesforum/
http://www.cliffshighperformance.com...machinesforum/
Burning Brakes
Joined: Mar 1999
Posts: 1,047
Likes: 3
From: CA
I've heard some great things about this guy in Wisconsin who specializes in Q-Jets: http://www.sparkyscarbs.com/
Don't know how far he is from you. Maybe he can help.
Don't know how far he is from you. Maybe he can help.
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Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
What is the number on your carb? (on the driver's side, verticle, it will start with either 70 or 170). This will give me a hint of how the carb might be set up to start with, which could help in tuning.
To get the idle dialed in, you need a vacuum meter. Hook it up to manifold vacuum. Gently seat the idle mixture screws (at the base of the carb in front) and then screw them out 3 1/2 turns each (that's a decent starting point).
Strart the car and set the idle speed with the screw you have been using, then check the vacuum reading.
Now, screw the mixture screws out a half turn each (be sure to always adjust them the same). Check that the idle speed has not changed, or, if it has, use the idle speed screw to re-set the idle speed where it was. Now, check the vacuum meter. If vacuum has increased, go out farther and check again. If it has decreased, screw them in one turn and check again (being sure to maintain constant idle speed)
What you are going for is the point at which you get the highest vacuum at idle.
God bless, Sensei
To get the idle dialed in, you need a vacuum meter. Hook it up to manifold vacuum. Gently seat the idle mixture screws (at the base of the carb in front) and then screw them out 3 1/2 turns each (that's a decent starting point).
Strart the car and set the idle speed with the screw you have been using, then check the vacuum reading.
Now, screw the mixture screws out a half turn each (be sure to always adjust them the same). Check that the idle speed has not changed, or, if it has, use the idle speed screw to re-set the idle speed where it was. Now, check the vacuum meter. If vacuum has increased, go out farther and check again. If it has decreased, screw them in one turn and check again (being sure to maintain constant idle speed)
What you are going for is the point at which you get the highest vacuum at idle.
God bless, Sensei
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
What is the number on your carb? (on the driver's side, verticle, it will start with either 70 or 170). This will give me a hint of how the carb might be set up to start with, which could help in tuning.
To get the idle dialed in, you need a vacuum meter. Hook it up to manifold vacuum. Gently seat the idle mixture screws (at the base of the carb in front) and then screw them out 3 1/2 turns each (that's a decent starting point).
Strart the car and set the idle speed with the screw you have been using, then check the vacuum reading.
Now, screw the mixture screws out a half turn each (be sure to always adjust them the same). Check that the idle speed has not changed, or, if it has, use the idle speed screw to re-set the idle speed where it was. Now, check the vacuum meter. If vacuum has increased, go out farther and check again. If it has decreased, screw them in one turn and check again (being sure to maintain constant idle speed)
What you are going for is the point at which you get the highest vacuum at idle.
God bless, Sensei
To get the idle dialed in, you need a vacuum meter. Hook it up to manifold vacuum. Gently seat the idle mixture screws (at the base of the carb in front) and then screw them out 3 1/2 turns each (that's a decent starting point).
Strart the car and set the idle speed with the screw you have been using, then check the vacuum reading.
Now, screw the mixture screws out a half turn each (be sure to always adjust them the same). Check that the idle speed has not changed, or, if it has, use the idle speed screw to re-set the idle speed where it was. Now, check the vacuum meter. If vacuum has increased, go out farther and check again. If it has decreased, screw them in one turn and check again (being sure to maintain constant idle speed)
What you are going for is the point at which you get the highest vacuum at idle.
God bless, Sensei
