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Old 04-24-2017, 08:36 AM   #1
Hacksaw
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Default Re: Qjet Question

Robert: Did you figure it out?
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Old 04-24-2017, 09:05 AM   #2
Robert Simpson
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Default Re: Qjet Question

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Originally Posted by Vic Santos View Post
Had this problem approx. 30 years ago. What happens is that when you shut the secondary throttle at high vacuum the pressure across the throttle blades holds them in place when you try to open them again especially if the bores are a little oxidized and the actuating lever is NOT PINNED TO THE SHAFT. The fix is to pin the throttle shaft to the actuating lever; do not rely on the torsion spring to open the throttle. A $.10 rollpin is most common fix.
Vic, I believe you are correct. When I pulled the carb off and started to play with it I discovered the spring holding the shaft. Even in the wide open position you could manually close the secondary on the baseplate. So I put a roll pin in it. I will see if this helps it this weekend. Everyone has given me some good advice and I appreciate it. I dial honest so I have not had this problem occur. It has just been recent when a couple of times I caught them real early and I just wanted to scrub a little. We will see thank you all.
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Old 04-24-2017, 12:38 PM   #3
Rich Biebel
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Default Re: Qjet Question

The secondary spring arrangement is not really very safe.

I once had that spring pop off and my throttle went wide open.

Engine sucked it wide open......

The car was on the trailer inside my garage. I was messing with something, probably the carb.

I revved it up a couple times and it went wide open.....

I shut the air valve with my hands and a friend managed to kill the ignition switch.....He hit the switch so hard it broke off.....but did shut it down....

I never saw it happen before that on any Q-Jet.....street car or race car...

The spring must not have been properly in place but it showed me what could happen.....

Drill and pin the lever to the shaft.....

Q-Jets are great when they work well.....but can really give you fits....
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Old 05-05-2017, 08:02 AM   #4
Robert Simpson
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Default Re: Qjet Question

Update. Removing the spring on the secondary shaft and pinning it was the key. I made a pass last weekend and drove past the finish line and pedaled it a couple times and it worked. I dial honest but now I know if I need to pedal it should respond ok. Thanks to all the suggestions it is appreciated. Now if I can just figure out how to lean up the mid range it would be good, any suggestions out there on that?

Robert
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Old 05-05-2017, 09:13 AM   #5
Mike Pearson
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Default Re: Qjet Question

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Originally Posted by Robert Simpson View Post
Update. Removing the spring on the secondary shaft and pinning it was the key. I made a pass last weekend and drove past the finish line and pedaled it a couple times and it worked. I dial honest but now I know if I need to pedal it should respond ok. Thanks to all the suggestions it is appreciated. Now if I can just figure out how to lean up the mid range it would be good, any suggestions out there on that?

Robert
Are you still using the metering rods in the primary jets. If so most are not using them any more. Drop down about 5 jet sizes on the primary jets and remove the primary metering rods and plug the hole where the power valve used to be. That should give you better control of the fuel metering
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