Torch Troubles

Admittedly, I don't use my torch much. I carry one small cylinder of propane and one small cylinder of MAPP. Both tanks have only been used a couple of times. They are stored on their sides in a toolbox in my Jeep, and they don't have any room to move around.

The MAPP still works fine. I get a nice sharp blue cone that stays lit. The propane, however, goes out the second I take the lighter away, and while it's lit, there is a lot of yellow in the flame, and the flame is not conical. The pressure in both tanks seem to be about the same.

Did something happen to that tank over time? I only have one tip. But the propane worked fine before with it.

What's the torch? Any clog in the tip? Is the tip a dual-fuel type? I used Surefire pushbutton-ignition torches back when they had a separate tip for Mapp gas. As for the tanks themselves, I just go by weight, as far as how much use is left.