I am having a problem getting this thing to idle. The bottom line is when I check for vacuum at idle there is none. If I am correct without vacuum at idle the fuel will not be pulled thru the idle circuits. My setup is as follows- 2 holley 660cfm carbs atop a ram manifold. The carbs have been modified where I have replaced the secondary metering block with a primary block. This was done about 3 yrs ago. When it was done it worked ok sometimes and was very sensitive to any adjustments. I now have a new engine and when I ran it on the trailer I was able to get the idle to work but at around 1000 rpms. I took it to the lake last week for the first time and it wouldn't idle at all. As soon as I let off the throttle it died. I hooked a vacuum guage to it and had no vacuum at low rpm only when I started to open the butterflys did the vacuum guage start to register. Since this was the first time out with the new engine when I got home I checked the plugs and noticed them to be very white(lean). The main jets that I was running were 68 all around. I put 72 in and will try it this weekend. I know by changing the main jets won't affect the idle. I took the carbs off and disassembled them and blew out all the passages again making sure there were no obstructions in the idle passages. One question, on the metering block there is a small jet called the idle restrictor is this the same as the idle jet?
I went back to square one and set both carbs exactly the same, idle mixture screws turned out 1 1/2 turns, the idle adj screw set so the butterfly is not exposing the idle slot in the carb bore. So my main concern is why I don't have vacuum at idle. I have checked for vacuum leaks and don't see any. Any suggestions would be appreciated.
Barry
Barry