Q-jet secondary metering rod question

Rusty Davenport · 05-11-2017, 08:18 AM

When an engine is at idle and there is no movement of the secondary metering rods or likewise the hanger, is the secondary metering rods having any effect on the fuel mixture as far as how rich or lean the engine is idling ??? Another way of asking--- are the secondary rods doing anything at idle ???

Greg Reimer 7376 · 05-11-2017, 10:07 AM

No. All fuel that goes past the secondary metering rods goes out the discharge nozzles under the secondary air valve blades. For any air velocity to occur there, the secondary throttle butterflies in the carb base plate have to be open. If air is passing through the secondary side of the carburetor, the butterflies have to be open, so if your engine is idling and a small air flow can be detected at the secondaries, they must not be seated.Check and see if they are hanging open.

Daran Summerton · 05-11-2017, 10:39 AM

Yes it will affect idle usually when float is high or pressure high. So does needle and seat size. Why I don't know.

Rusty Davenport · 05-11-2017, 12:00 PM

Thanks to all who provide input.......I am still experimenting with making the 2 step work with a quadrajet without sacrificing ET. I am trying some low rpm stuff instead of WOT......thanks again.

Kevin Panzino · 05-11-2017, 06:02 PM

Check your PM's Rusty....

Kevin

Everett Vassar · 05-12-2017, 12:35 AM

We are still struggling with the transition from Holley to QJ. At dallas the EGT logger recorded 1544 deg which I thought was lean. I pulled the rods and went to see Mr Braswell. He handed us a pair about 4 sizes smaller and said go try these. Did not improve E.T. did not drop EGT either. But Dustin said the car was acting a little stubborn starting and cruising to the lanes. I noticed he was struggling with staging.apparently some fuel was getting past the rods.. so the old rods went back in. I should have our other Qjet back from Deano this week

05-11-2017, 08:18 AM	#1
Rusty Davenport Senior Member Join Date: Jun 2005 Location: Nashville N.C. Posts: 506 Likes: 4 Liked 101 Times in 27 Posts	Q-jet secondary metering rod question When an engine is at idle and there is no movement of the secondary metering rods or likewise the hanger, is the secondary metering rods having any effect on the fuel mixture as far as how rich or lean the engine is idling ??? Another way of asking--- are the secondary rods doing anything at idle ??? __________________ NHRA AND IHRA STOCK ELIMINATOR 2772

05-11-2017, 10:07 AM	#2
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,135 Likes: 172 Liked 704 Times in 218 Posts	Re: Q-jet secondary metering rod question No. All fuel that goes past the secondary metering rods goes out the discharge nozzles under the secondary air valve blades. For any air velocity to occur there, the secondary throttle butterflies in the carb base plate have to be open. If air is passing through the secondary side of the carburetor, the butterflies have to be open, so if your engine is idling and a small air flow can be detected at the secondaries, they must not be seated.Check and see if they are hanging open.

05-11-2017, 10:39 AM	#3
Daran Summerton Senior Member Join Date: Jun 2003 Location: Las Vegas nv Posts: 600 Likes: 18 Liked 66 Times in 37 Posts	Re: Q-jet secondary metering rod question Yes it will affect idle usually when float is high or pressure high. So does needle and seat size. Why I don't know. __________________ 72 cutlass Last edited by Daran Summerton; 05-11-2017 at 10:49 AM.

05-11-2017, 12:00 PM	#4
Rusty Davenport Senior Member Join Date: Jun 2005 Location: Nashville N.C. Posts: 506 Likes: 4 Liked 101 Times in 27 Posts	Re: Q-jet secondary metering rod question Thanks to all who provide input.......I am still experimenting with making the 2 step work with a quadrajet without sacrificing ET. I am trying some low rpm stuff instead of WOT......thanks again. __________________ NHRA AND IHRA STOCK ELIMINATOR 2772

05-11-2017, 06:02 PM	#5
Kevin Panzino Senior Member Join Date: Oct 2002 Location: Pittsburgh Posts: 575 Likes: 298 Liked 747 Times in 136 Posts	Re: Q-jet secondary metering rod question Check your PM's Rusty.... Kevin

05-12-2017, 12:35 AM	#6
Everett Vassar Member Join Date: Jun 2004 Location: Kennedale,Tx Posts: 227 Likes: 0 Liked 2 Times in 2 Posts	Re: Q-jet secondary metering rod question We are still struggling with the transition from Holley to QJ. At dallas the EGT logger recorded 1544 deg which I thought was lean. I pulled the rods and went to see Mr Braswell. He handed us a pair about 4 sizes smaller and said go try these. Did not improve E.T. did not drop EGT either. But Dustin said the car was acting a little stubborn starting and cruising to the lanes. I noticed he was struggling with staging.apparently some fuel was getting past the rods.. so the old rods went back in. I should have our other Qjet back from Deano this week