If there is spark but no ignition, then it seem to me the spark is in the wrong place. It sounds like it need to be moved by adjusting until the spark happens in the gas stream, so that it will ignite. I would have also considered there being air in the line or the propane being too old, if it has not ignited when you used a flame. But if it works when you ignite it with a flame, I don't think you can have a serious problem. If there is spark but no ignition, then it seem to me the spark is in the wrong place. It sounds like it need to be moved by adjusting until the spark happens in the gas stream, so that it will ignite. I would have also considered there being air in the line or the propane being too old, if it has not ignited when you used a flame. But if it works when you ignite it with a flame, I don't think you can have a serious problem.

Piezoeelectric sparks find the easiest path to ground.. If the spot where you want the spark to go is dirty or farther away it goes to the closest clean spot.nearby that is grounded By adjusting the tip of the igniter wire and or cleaning it and its target you may be able to direct itts path. Piezoelectric igniters work by impacting a quartz crystal with a metal piece. Or between a metal anvil and a hammer the crystal when stressed or squeezed gives off a high voltage electrical charge Electronic scales use the same principle without the impact.. If the mechanism is weak and provides a weak snap you may get a weak spark that is not enough to ignite the gas. Another problem is the insulation on the igniter wire. Any gap closer than the tip to ground and the spark goes where itm is easier. the tip,is usually in or near the flame. You need something that can handle heat like PTFE tubing. Superr glue will work for a while to patch a bzre spot or coat the tip. You may have to open a path tto thee wire if it is coated on the very end. that is the most common place that insulation fails and I would guess right that this is the problem you have Piezoeelectric sparks find the easiest path to ground.. If the spot where you want the spark to go is dirty or farther away it goes to the closest clean spot.nearby that is grounded By adjusting the tip of the igniter wire and or cleaning it and its target you may be able to direct itts path. Piezoelectric igniters work by impacting a quartz crystal with a metal piece. Or between a metal anvil and a hammer the crystal when stressed or squeezed gives off a high voltage electrical charge Electronic scales use the same principle without the impact.. If the mechanism is weak and provides a weak snap you may get a weak spark that is not enough to ignite the gas. Another problem is the insulation on the igniter wire. Any gap closer than the tip to ground and the spark goes where itm is easier. the tip,is usually in or near the flame. You need something that can handle heat like PTFE tubing. Superr glue will work for a while to patch a bzre spot or coat the tip. You may have to open a path tto thee wire if it is coated on the very end. that is the most common place that insulation fails and I would guess right that this is the problem you have