Q jet power piston spring

john billups · 12-21-2024, 03:16 PM

Need a little help with the best spring . I have s spring set with 5 spring different colors and length.
80 g body w / 305 .

My problem is the motor wont idle. It acts like it go's rich and dies. I have vary low vacuum so I'm thinking the power valve is opening at idle and
dumping fuel.
My question is should, I use a tall spring or a short spring or just test till one that works
thanks, John

Danny Ashley · 12-21-2024, 03:32 PM

It is a street car or racecar?

john billups · 12-21-2024, 03:39 PM

stocker. w/ stocker cam short lift long duration.

MR DERBY CITY · 12-21-2024, 06:15 PM

Could possibly be a vacuum leak ?? Has the intake been removed lately ?

outlaw · 12-21-2024, 07:02 PM

Spring shouldn’t affect idle. Power piston is tied to main circuit not idle circuit if pulling fuel from main circuit at idle throttle blades are to far open.

john billups · 12-21-2024, 09:55 PM

Checked for vac leak w/ smoke machine.

As for the pistons. I thinking maybe a little pull over .

Well I'll put it back together as it's a backup and work on it next spring.

thanks all who chimed in.

John B645

Danny Ashley · 12-22-2024, 07:22 AM

PM sent

Terry Cain · 12-22-2024, 12:34 PM

Put flat edge on top base sitting upside down. Must be good and flat.

Kevin Panzino · 12-23-2024, 09:09 AM

Get a drinking straw, cut it down to about 4? long. Place it in the vent stack
at abslight angle to catch the power piston/primary metering rod hanger arms. Note the length sticking up. Now start the engine. It should pull the power piston down and the straw with it. If it goes down and stays down
At ?idle? (yes I understand it won?t idle well on its own but you get the idea) then that?s not your problem.
Have you drilled the holes in the primary blades yet?

Kp

monte385 · 12-23-2024, 09:23 PM

Get rid of PP & rods & block the vac. supply, reduce jet size.

12-21-2024, 03:16 PM	#1
john billups Junior Member Join Date: Dec 2005 Location: Portland ,OR Posts: 16 Likes: 0 Liked 0 Times in 0 Posts	Q jet power piston spring Need a little help with the best spring . I have s spring set with 5 spring different colors and length. 80 g body w / 305 . My problem is the motor wont idle. It acts like it go's rich and dies. I have vary low vacuum so I'm thinking the power valve is opening at idle and dumping fuel. My question is should, I use a tall spring or a short spring or just test till one that works thanks, John Last edited by john billups; 12-21-2024 at 05:21 PM.

12-21-2024, 03:32 PM	#2
Danny Ashley Member Join Date: Nov 2001 Location: Marion,In. Posts: 267 Likes: 60 Liked 110 Times in 29 Posts	Re: Q jet power piston spring It is a street car or racecar?

12-21-2024, 03:39 PM	#3
john billups Junior Member Join Date: Dec 2005 Location: Portland ,OR Posts: 16 Likes: 0 Liked 0 Times in 0 Posts	Re: Q jet power piston spring stocker. w/ stocker cam short lift long duration.

12-21-2024, 06:15 PM	#4
MR DERBY CITY VIP Member Join Date: Feb 2014 Location: Derby City, USA Posts: 3,611 Likes: 1,071 Liked 7,794 Times in 1,497 Posts	Re: Q jet power piston spring Could possibly be a vacuum leak ?? Has the intake been removed lately ?

12-21-2024, 07:02 PM	#5
outlaw Member Join Date: Aug 2008 Posts: 137 Likes: 78 Liked 132 Times in 52 Posts	Re: Q jet power piston spring Spring shouldn’t affect idle. Power piston is tied to main circuit not idle circuit if pulling fuel from main circuit at idle throttle blades are to far open.

12-21-2024, 09:55 PM	#6
john billups Junior Member Join Date: Dec 2005 Location: Portland ,OR Posts: 16 Likes: 0 Liked 0 Times in 0 Posts	Re: Q jet power piston spring Checked for vac leak w/ smoke machine. As for the pistons. I thinking maybe a little pull over . Well I'll put it back together as it's a backup and work on it next spring. thanks all who chimed in. John B645

12-22-2024, 07:22 AM	#7
Danny Ashley Member Join Date: Nov 2001 Location: Marion,In. Posts: 267 Likes: 60 Liked 110 Times in 29 Posts	Re: Q jet power piston spring PM sent

12-22-2024, 12:34 PM	#8
Terry Cain Senior Member Join Date: Feb 2008 Location: Georgetown, Indiana (close to Louisville, KY) Posts: 774 Likes: 530 Liked 230 Times in 106 Posts	Re: Q jet power piston spring Put flat edge on top base sitting upside down. Must be good and flat. __________________ Terry Cain ???? STK tcain19689585@gmail.com

12-23-2024, 09:09 AM	#9
Kevin Panzino Senior Member Join Date: Oct 2002 Location: Pittsburgh Posts: 573 Likes: 293 Liked 746 Times in 136 Posts	Re: Q jet power piston spring Get a drinking straw, cut it down to about 4? long. Place it in the vent stack at abslight angle to catch the power piston/primary metering rod hanger arms. Note the length sticking up. Now start the engine. It should pull the power piston down and the straw with it. If it goes down and stays down At ?idle? (yes I understand it won?t idle well on its own but you get the idea) then that?s not your problem. Have you drilled the holes in the primary blades yet? Kp

12-23-2024, 09:23 PM	#10
monte385 Junior Member Join Date: Oct 2015 Posts: 60 Likes: 44 Liked 27 Times in 19 Posts	Re: Q jet power piston spring Get rid of PP & rods & block the vac. supply, reduce jet size.