i tryed puting the vaccum advance on the top front passenger side port on my holly 4160 600cfm. it ran like crap so i put it back on the front bottom and now it is running great again.
and dont plug the crank case breather hole or the pcv valve , i know beter when i did it but ..what makes it so bad was i just steamed the engine bay and under carage ,now i get to do it all again..
oh what fun ill never learn

 

shane74


Did you initially set the timing without unplugging the vacuum advance hose from the distributor? If so, the timing was retarded when you hooked to a part throttle vacuum supply. Which would have made it run like crap.

You need to unplug the vacuum advance hose from the distributor then set the timing to 10 - 12 degree's BTDC, then hook it back up. Drive it and see if it pings, go through the steps I mentioned to you in the other post.

 

Check the vacuum port on the passenger side of the metering block which you have your vacuum advance hooked to. While the engine is running at idle it should have no vacuum at idle. If there is any amount of vacuum at this port then you have the throttle plate opened to far and are actually not using just the idle circuit of the carburetor at idle. Some adjustments are in order if the above is happening. If you cannot get your engine to idle properly without having vacuum at the metering block vacuum port, then something is wrong.

On way to determine if you have an internal carburetor problem or just an idle adjustment problem is to adjust the idle mixture screws in and then back out to specs one at a time. When this is done while the engine is idling, the engine will all but die. If no obvious change in idle occurs while performing this test then the carburetor is in need of adjustment because it may not be using the idle circuit for idling or there is an internal carburetor problem.

I have seen plenty of engines that are worn enough that they would not idle at normal rpms without adjusting the throttle plates too far open and then are not using the idle circuit of the carburetor. Improper timing and low compression are the usual culprits that cause this. Bad ignition components are also causes, but that is easy to detect when driving around and you feel the when the engine missfires and such.

 

IM RECHECKING EVERY THING THIS WEEKEND TO MAKE DOUBLE SURE. I HADE HOLLEY EMAIL ME THE ADJUSTMENT PROCEDURES SO THERE WONT BE ANY MISTAKES
THANK FOR THE ADVICE

 

You don't have to yell shane.

 

sorry didnt relise caps were on, im blamin it on rap music an politics

 

Have you found anything wrong with your engine? How is it running?

 

ok my bad . i ended up with the vacum back on the top were it belongs ,now it eats mud hole like it should.