q-jet problem modified 350
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
today i tried to tightening the spring,but there was no difference,then to loose it,also no difference...there is always this flat spot when i shift from first to second,second to third and so on....when i shift very slowly then there is no flat spot...
sorry again for my bad english
sorry again for my bad english
Last edited by PAmotorman; Mar 24, 2014 at 11:28 AM.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
First, to correct statements made in earlier posts, the Q-Jet is not a vacuum secondary carb. It's a mechanical secondary carb with an airvalve. The airvalve is not vacuum operated - it is mass flow operated. For a complete description of the Q-Jet secondary system, simply e-mail me a request for a copy of my Q-Jet paper.
Regarding the setup of the carb and the bogging problem, there are about a half-dozen different issues that can all cause that problem, most of which come back to a lean condition which can be induced either by lack of secondary control or jetting and fuel supply.
Set your carb up as outlined in the "Quickie Performance Setup" section of my paper and it will run just great with that cam and head combo.
Lars
V8Fastcars@msn.com
Regarding the setup of the carb and the bogging problem, there are about a half-dozen different issues that can all cause that problem, most of which come back to a lean condition which can be induced either by lack of secondary control or jetting and fuel supply.
Set your carb up as outlined in the "Quickie Performance Setup" section of my paper and it will run just great with that cam and head combo.
Lars
V8Fastcars@msn.com
Thread Starter
Intermediate
Joined: Mar 2014
Posts: 26
Likes: 0
From: Vienna
First, to correct statements made in earlier posts, the Q-Jet is not a vacuum secondary carb. It's a mechanical secondary carb with an airvalve. The airvalve is not vacuum operated - it is mass flow operated. For a complete description of the Q-Jet secondary system, simply e-mail me a request for a copy of my Q-Jet paper.
Regarding the setup of the carb and the bogging problem, there are about a half-dozen different issues that can all cause that problem, most of which come back to a lean condition which can be induced either by lack of secondary control or jetting and fuel supply.
Set your carb up as outlined in the "Quickie Performance Setup" section of my paper and it will run just great with that cam and head combo.
Lars
V8Fastcars@msn.com
Regarding the setup of the carb and the bogging problem, there are about a half-dozen different issues that can all cause that problem, most of which come back to a lean condition which can be induced either by lack of secondary control or jetting and fuel supply.
Set your carb up as outlined in the "Quickie Performance Setup" section of my paper and it will run just great with that cam and head combo.
Lars
V8Fastcars@msn.com
thank you Lars!!!!
