I've been having this same problem for a while now. I took off the top of my carb and connected the linkage for the choke back up where the previous owner had taken it apart. My truck doesn't seem to want to kick into the fast idle. The choke seems to be working perfectly. It just doesn't pick up the fast idle. I can manual put it into the fast idle and it works great, but when I start the truck in the morning it doesn't want to engage the fast idle. I don't necessarily have the money to replace the Vacuum Advance, and I don't think this is even the problem here. The truck is a 87 22r. Any help would be greatly appreciated.