76 qjet primaries running lean

Ok so mark helped me in my other thread about my secondaries and that helped wot a bit. Now I need to get my primaries squared away. Can I back out the APT screw to make the primary rods raise up higher during part throttle with no I'll effects? Here's my issue using the 375/ 41 center plate and weights base timing is set at 10 degrees btc maxed out at 32+ 8 from the accel vac can. The engine diesels a little at shut down. I know its not the timing because ig I put on the eddy 1406 the problem goes away... But so does all the power and responsiveness:-( any help is appreciated. Here's a link that describes my prob. Post #8

http://www.hotrodders.com/forum/initial-timing-related-dieseling-181136.html

 

I still think your run on is timing or fuel quality related. I don't know why changing carbs would have an effect except tit doesn't want to run with that eddy anyway, haha. Have you tried going up in fuel to 93 or something?

You can adjust the apt for response at part throttle. You might want to go up a size on jets.

 

Yeah I did notice it goes away when 93 octane is used, so I figured a more rich setup would work. I can tell the engine wants more

 

I always run 89 though

 

Dieseling is caused by one thing: fuel is being delivered to the engine and ignited by heat. Typically, the cause is a throttle open too far. This can be the result of retarded timing, or a lean mixture. Your suggestion, however, enriching the off idle will not work. Why? The off idle circuits, the ones controlled by the part throttle adjustments are not operating at that point. There are several things to try. One is the ignition timing. Try adjusting the timing, the initial timing, a few degrees advanced. Any engine changes made will affect the correct timing adjustments. This may alleviate a slight bog, or surge at part throttle, and since it will raise the idle, it will allow a reduction in the throttle opening at idle. Another is to adjust the idle mixture to optimum. Typically, the idle misture is adjusted slightly lean, causing the throttle to be opened, frequently enough to cause dieseling. A third is to be sure ALL of the adjustments are correct. This includes the solenoid controlling the throttle when the key is on. It is very frequent for me to see that this solenoid is either defective, or mis-adjusted, causing you to have to raise curb idle using the throttle stop screw. This solenoid is intended to hold the idle to an acceptable speed, with a slightly open throttle, and when the key is turned off, the solenoid de-energizes, allowing the throttle to close completely. Ray

 

What is the carburetor number? What are the engine specifications, CID, cam specs, true static compression ratio. Exactly what has been done to the carb? Jet size, primary metering rods used, idle tubes, airbleeds, down channel and idle bypass air?......Cliff