How do I know if my secondaries are working?
Pro
Joined: Jul 2001
Posts: 710
Likes: 0
From: Thornton Co
Re: How do I know if my secondaries are working? (virtue4u)
secondaries are locked closed at idle. the only way to open them manually is by opening up your primary throttle and then opening them. a good way to check them when you are running is to attach a wire on the down shaft from your vaccum so that is fairly tight but still loose enough to move so that when you drive it at full throttle you can see if it moves the paper clip or wire of your choice down the shaft. or you can have someone ride under your hood at full throttle and tell you.(not the recommended way)
Le Mans Master
Joined: Dec 2000
Posts: 7,245
Likes: 4
Re: How do I know if my secondaries are working? (virtue4u)
If you can't feel the secondaries kicking in when you stick your foot in it......then I have the cure.......buy a big block :lol: :lol: :lol: :lol: :lol:
:jester
:jester
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Re: How do I know if my secondaries are working? (67HEAVEN)
When you put it to the floor and it doesn't go
Wooooooowwwwwww!!!then you have a problem. :D
If the carb is older and hasn't been rebuilt the diaphram that opens the secondaries could be torn, check that.
[Modified by MotorHead, 10:10 PM 10/28/2001]
Wooooooowwwwwww!!!then you have a problem. :D
If the carb is older and hasn't been rebuilt the diaphram that opens the secondaries could be torn, check that.
[Modified by MotorHead, 10:10 PM 10/28/2001]
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Re: How do I know if my secondaries are working? (Vetteboy)
Easy way to check, I am assuming a Q-Jet here.
Q-Jet consists of secondary metering plates that mechanically opened and an air valve that is opened by demand.
-If you take the aircleaner off and blip the throttle hard at idle, the air valve may open (it is spring loaded).
-To check plates, with the engine OFF, open the throttle all the way by hand. While holding it open, push the air valve open and make sure the secondaries are open.
-To check at full throttle on the road, try this. On the passenger side of the carb, there is the secondary lockout that prevents the secondaries from opening when the choke is engaged. With a piece of wire, tie this up so the secondaries will not open. Now test drive. If car is a dog at full throttle, then the secondaries normally work (BTW Corvettes hatre 2 bbl carbs. :D )
Hope this info helps, Good luck.
Q-Jet consists of secondary metering plates that mechanically opened and an air valve that is opened by demand.
-If you take the aircleaner off and blip the throttle hard at idle, the air valve may open (it is spring loaded).
-To check plates, with the engine OFF, open the throttle all the way by hand. While holding it open, push the air valve open and make sure the secondaries are open.
-To check at full throttle on the road, try this. On the passenger side of the carb, there is the secondary lockout that prevents the secondaries from opening when the choke is engaged. With a piece of wire, tie this up so the secondaries will not open. Now test drive. If car is a dog at full throttle, then the secondaries normally work (BTW Corvettes hatre 2 bbl carbs. :D )
Hope this info helps, Good luck.
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: How do I know if my secondaries are working? (virtue4u)
I had been wondering the same thing. I couldn't figure out why if I blipped the throttle with the air cleaner off I couldn't get the secondaries to open. Turns out you can't generate enough vacuum to open 'em up. Plus, if the choke has not fully disengaged it hold the secondaries closed.
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Le Mans Master
Joined: Mar 1999
Posts: 6,744
Likes: 1
From: delmont pa
Cruise-In I Veteran
Cruise-In II Veteran
Re: How do I know if my secondaries are working? (thebruce)
all carbs,both holley and q jets have a full open stop for the secondary,just find that, put a dab of grease on it and go for a ride. when you come back check the grease for a mark. works every time. :chevy
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: How do I know if my secondaries are working? (virtue4u)
I just cured a problem in this area so here goes. Over the past winter I gutted the interior and reinsulated it with "The Insulator" from Jegs. This insulation is about 1/2 thich and comes in 4' by 6' rolls. I cut it to fit and then reinstalled the interior. Over the past summer the car seemed sluggish and a few weeks ago I found the problem. The extra insulation wasn't allowing the throttle to open fully and also wasn't allowing the secondaries to open. I bent the gas pedal to take up the slack and it was like plugging in another 50 horsepower. Moral...Make sure your primaries are opening all the way before you start to worry about the secondaries. :seeya
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 65,981
Likes: 15
Re: How do I know if my secondaries are working? (virtue4u)
I am getting a kick when I open it up, but since this is my first vette, I wanted to make sure that I wasn't missing something. The fact that I couldn't open my secondaries by hand at idle concerned me. It sounds (and feels) like I'm OK. Corvette forum members come through again. Thanks.
