random popping in the exhaust manifold

[hueyhoolihan]

i'm getting a consistent and random popping noise that's emanating from somewhere between the exhaust manifold and the muffler. it happens every few seconds or so. there is also a consequent power loss too. also, a bit of hesitation on a quick blip of the accelerator pedal (not sure they are related though, as it think i may need to adjust or buy a new accelerator pump)

the popping occurs at all times and at all RPMs and intervals between occurrences increases with RPMs. the car is stationary as so there is no load on it, but i have reason to believe that it occurs even with a load. there is no relationship with overrun or deceleration that i can detect. it's almost as if the fuel is failing to burn in a random cylinder, is expelled into the exhaust header and only then burns with such speed and intensity as to create an audible popping noise.

in an attempt to determine whether or not the problem is related to carburation or ignition, i did the following:

with the engine off, i removed a sparkplug wire, started the engine and let it idle on seven cylinders and listened for the random popping. then stopped the engine. i repeated the test seven more times with a different wire each time.

the popping never varied. it was always random and of the same intensity and the engine idled on seven cylinders identically in each case.

i'm, for the time being, thinking that it shows a likelihood of a carburation problem rather than an electrical one. as each of the eight tests showed that all of the elements of each spark circuit; the plug, the wire, that post on the cap, and that lobe on the shaft of the distributor had no effect on the popping.

what say ye? does the test prove anything at all, or was it just wishful thinking? it's not as if i'm incapable of that, you know.

the car (1941 Ford convertible) was a show car that i recently purchased and was not running when purchased. with a new set of points and condenser it now runs and starts with the 8v battery (for the time being) that was in it when purchased. i haven't put any gasoline in it either, so there's no telling how old it is...