If you plan on working on the carb much, that book and a copy of the GM Chevrolet Chassis Service Manual are necessary reference materials.
Q-jet seting question
Thread Starter
Navigator
Joined: Oct 2010
Posts: 9
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Q-jet seting question
Hello
Another question about q-jet .. sorry , i dont speak verry well Englisch .. better i will show it on picture :-) .. i dont know what the name is for this part .. this part set how high or how low the needles have to be on iddle speed. My question is
How to set it correctly ??? What to take car on taht the seting will be correct ??
Thank You for Yoru help
[IMG]
[/IMG]
Another question about q-jet .. sorry , i dont speak verry well Englisch .. better i will show it on picture :-) .. i dont know what the name is for this part .. this part set how high or how low the needles have to be on iddle speed. My question is
How to set it correctly ??? What to take car on taht the seting will be correct ??
Thank You for Yoru help
[IMG]
[/IMG]
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
That is the power piston, and the adjustments are to raise or lower it in the bore and to select the proper spring for it. The expert on this is Lars Grimsrud and you can send him an e-mail requesting info on how to properly set it for your engine/car. Include details of the engine (not details on the individual components; but engine displacement, approx. HP and torque, max RPM limits, how much vacuum your engine makes at idle, transmission type, and how you will be using the car) in your e-mail and he will advise you on how to proceed. Lars e-mail address is V8FastCars@msn.com .
Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
My Q-Jet Tuning Paper outlines the setting and process for the APT adjustment. Just e-mail me for a copy of the paper.
Lars
V8FastCars@msn.comC
Lars
V8FastCars@msn.comC
Thread Starter
Navigator
Joined: Oct 2010
Posts: 9
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Thank You
I have order the book - 14,93 $ is for sure worth .. thank You .. i know You are the best, guys. All the Help comme so fast.
That books will arrive to me in 2 weeks .. is between be someone abble to inform me about how to set this part show on picture, i have to put the carburetor togever by tomorrow and .. i have 3 other q-jets .. all of them have it set 3 and 1/4 turn off from the deepest point ( i mean maximum turn in and then 3 and 1/4 turn out ) ..is this correct ??? or have the carburetors all wrong setings ??
That books will arrive to me in 2 weeks .. is between be someone abble to inform me about how to set this part show on picture, i have to put the carburetor togever by tomorrow and .. i have 3 other q-jets .. all of them have it set 3 and 1/4 turn off from the deepest point ( i mean maximum turn in and then 3 and 1/4 turn out ) ..is this correct ??? or have the carburetors all wrong setings ??
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
My Q-Jet Tuning Paper outlines the setting and process for the APT adjustment. Just e-mail me for a copy of the paper.
Lars
V8FastCars@msn.com
Lars
V8FastCars@msn.com
Email Lars!
Lars, looks like your email address grew another 'C' on the end! lol.
Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
Good catch - trying to type too fast... My e-mail address is:
V8FastCars@msn.com
Hey LearningVette - One thing I noticed in your photo is that the carb you are working on is a commercially rebuilt Q-Jet. That carb is likely to have a ton of problems, and will likely need significant repair work far beyond the normal "rebuild kit" installation - you may not be able to get that carb running right due to alterations done by the commercial builder. Be sure to read my "Commercially Rebuilt Q-Jet Problems" paper for some cautions on the carb you have.
Lars
V8FastCars@msn.com
Hey LearningVette - One thing I noticed in your photo is that the carb you are working on is a commercially rebuilt Q-Jet. That carb is likely to have a ton of problems, and will likely need significant repair work far beyond the normal "rebuild kit" installation - you may not be able to get that carb running right due to alterations done by the commercial builder. Be sure to read my "Commercially Rebuilt Q-Jet Problems" paper for some cautions on the carb you have.
Lars
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Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
It's been media blasted - inside and out - removing all original finishes. Only the cheap commercial builders - the ones who really hack a carb - do that.
Lars
Lars
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Was wondering the main problem with cheapo rebuild's, but this pretty much explain's it. Glad the Q-Jet on my car is an original, custom jetted for my application. The carb work's great, and wouldn't trade it for anything else.
