My Portasol Super Pro butane-powered soldering iron will not ignite, despite fuel tank being full, and the piezoelectric igniter seems to be working. Noted that another member reported similar problems about 8 months ago

what do you want , look at the size of the tank and know it will not last for months on end

Gas (condensation really) may be freezing and constricting flow. Try warming the tip a bit with a hair dryer see if it goes longer.

Any butane will work, but the big name-brands are usually filtered better and less likely to cause problems. The biggest issue is the nozzle -- there are a lot of different sizes. Any Weller butane can will fit perfectly (usually cheapest at the local Sears store), but any can with multiple adapters will also work.

If you have an old can that fits, save the nozzle when it's empty. It should fit a different can if you can't find a can that fits the tool.

Not enough information. That's an extremely vague description of the problem. There's no way to suggest a fix without knowing more about it.

Does it spark?
Does butane come out of it?
Is the cylinder full?
Do the switches move properly?
How old is it? How much use has it seen?
Is it an intermittent problem, or constant?

I have the same soldering iron and have found for this problem, the replaceable tip has worn out.
All you need to do is buy a replaceable tip of your choice. The tips are a consumable part that wears out.

I have the same issue. I overcame it by replacing the tip with a new one. I estimate I get about a year from a tip. I cannot tell why the old tips make the pyropen hard to ignite.

Does it spark?
Does the butane come out?
How old is it, and how much has it been used?
Did you put cheap butane in it at some point?

It is supposed to produce heat there, it's the place where catalytic combustion takes place. If the tip doesn't heat up enough, it means that either the tip is not screwed properly into the housing, or there's not enough gas pressure. The catalytic mesh should be orange in color when heated properly.
Too low gas pressure may be a result of many things, like a malfunctioning valve (regulator and/or on/off),or clogging of the ceramic pressure reductor due to poor quality gas used, with high heavy fraction content.

It's not the solder you use for the soldering tool but the correct solder for the JOB you are doing with the tool.
Read the packages and pick the right mix/flux/thickness etc for the metal/connectors/etc you are soldering.

butane is butane it all works