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Author Topic:   Q-Jet Help
DEEDDUDE
Dirt Full Roller

Total posts: 56
posted April 13, 2001 07:07 PM
Have a problem with the secondaries. Every time I rev the motor the secondaries open and will not close all the way, make the motor turn about 2000 rpms instead of going back to idle. What would cause this? Any help is appreciated. Deed

g400
Dirt Roller

Total posts: 9
posted April 13, 2001 09:03 PM
Are you turning it up enough to make the 4-barrel kick in or does it do it with just a little throttle application?

DEEDDUDE
Dirt Full Roller

Total posts: 56
posted April 13, 2001 09:49 PM
I should have mentioned that the secondary throttle plates close but, the upper butterflies stay open a little. This causes the secondary rods to stay up, which in turn draws fuel from somewhere. You can see the fuel flowing between the body and the upper butterflies. The only way to stop this is to rev the motor again and it quits. But, rev it a third time and the problem comes back. I turn the motor up quite a bit, 5000-6000. I just touch it a little to close the uppers. Could it be the vaccum diapham not getting enough vaccum????????? Deed

g400
Dirt Roller

Total posts: 9
posted April 14, 2001 10:27 AM
There is a spring and lock ***** on the upper rear butter fly that controls the opening of the rear.I have seen the spring break and also the lock ***** will loosen and allow the rear to stay open.Also have had to polish the upper butter fly's around the edges so they would return all the way back.Also have loosened the butter fly's and adjust them a little on the shaft to get them to return to the closed position.Make sure the bottom base plate butter fly's are completely closing on the rear.You mentioned something about a vacuum diapram,but if we are talking about a 4-barrel q-jet it opens the rear 4-barrel by the intake vacuum as the engine load is increased(heavy excelleration).I hope i am in the area you are talking about.

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