Hi guys, I need a guidance how to adjust my Qjet (mixing). Its working on the 430 engine . In advance many thanks. Klaus
First, is the Q-Jet original, or a re-manufactured unit? The re-manufactured Q-Jets are not useful, they are only good for passing USA emissions testing. They can not be tuned properly, since they are assembled from a random batch of used parts which only appear to be correct. Also, unless the carburetor is properly rebuilt with the idle tubes replaced, there is likely debris under the tubes which will interfere with the idling. Also, you need to ensure the correct intake manifold gaskets are in place, and that they are in good condition. If anything is wrong with them, you will have vacuum leaks and tuning will not be possible. For the same reason, you need to ensure your primary throttle shaft has no leaks. If you can rattle the primary throttle shaft in the base plate (hold linkage to gas pedal and move back and forth), there is excessive wear in the base plate (throttle-body), and there will be constant vacuum leaks which can never be tuned out. The carburetor will need a rebuild. If your carburetor is correctly rebuilt, and all of your gaskets are new and correctly assembled, then tuning can begin. Set idle speed at 650-700 RPM in park, with each mix screw 2-1/2 - 3 turns out. Once warm, set ignition timing per factory specs.
Hi Len, The qjet is original. And no Lenks are on the mixing unit, but I have to Check if I can rattle the throttle shaft....In this case I am not sure. I have set the ignition timing according factory specs few months ago , do I have to set again after setting the mix screws¿ Regards Klaus
