Surging When Cold

[LaneRover]

My brother once had a gummed up mechanical fuel pump that would allow him to drive for a bit and then lose power.

Could yours be gummed up in a way that doesn't affect it when warm?

[utahseries]

We've gone through the whole system from the tank to the carb and we can't find anything out of the ordinary, so it's most likely a vacuum leak. And to answer your question Bugeye, they are all running like a dream!

[stomper]

When looking for the vacuum leak, pay particular attention to the joint between the exhaust manifold and the intake manifold. It may be hard to squirt carb cleaner on this joint, but I'm guessing there is where the problem is. The cast iron exhaust manifold and the aluminium intake has a gasket between them that is likely perished.

[cedryck]

You can use a propane tourch to find a vacume leak as well, this works great, just do not light it, use it with the flame OUT obviously.