Topic: Carburetor Woes
Trying to get this art car roadworthy. '64 Dart with 225 slant six fed by a 1-barrel Holley 1920. I got the carb from a friend, who had it reportedly running well on this same engine before we pulled the engine from its donor car a year and a half ago. I believe it was a store-bought reman unit.
The engine behaves like it has a big vacuum leak. When hot, it will only stay running with the choke engaged. It won't run at all below 1500ish RPM, and the need for choke drops off with higher RPM. I checked everywhere with a can of starting fluid and can't find a leak, including carb base, vacuum lines, and intake manifold to head connection. Blocking off the PCV line helps a little, but not enough. Either I'm missing a big source of unmetered air, or its just not getting enough fuel in the main circuit. I took the bowl off, and everything looked clean, no obvious gunk. The main jet was clear. I tried stepping up two jet sizes and it didn't make much difference, if any. There may be a clog somewhere deeper in the carb, but who knows where. I installed a new fuel filter before firing it up, and the gas in the tank isn't that old.
The kicker is that it was behaving fine in the garage yesterday (in neutral). Then when I was idling it today to check the trans fluid, it suddenly died and started exhibiting the above symptoms upon restart. The only thing I know that has changed is the exhaust manifold choke stove stopped working, but I don't recall the engine running with very much choke engagement before that. You don't just develop a huge vacuum leak that suddenly, and I can't find a leak anyway, so I'm thinking something in the main fuel circuit suddenly got partially clogged.
I was planning to take this thing on a road trip this weekend. Anything else I should check before tearing this carb apart, or wiring the choke plate partially closed and dealing with a very narrow band of usable throttle?