I use a pepsi can stove as well. I made it myself which is why it probably takes a little while to get going. AsABat is right, priming with alcohol on the rim can help it get going, but when it does get going it is so sweet. The pressure of the gasses in the wall make it look like a gas hob on a kitchen stove.
Just a side note, the actual reason i replied to this thread. I didn’t want the hassle of making/carrying a pot stand so added a pretty cool built in pot stand. Get four 8d nails (not galvanised) and cut off the nail heads. Measure first as what you going for is to mount the nails on top of the pepsi stove, about 3/8" from each edge. Glue them to the can using J.B Weld or any high heat tolerence glue/epoxy. Glue the other two nails in the same fashion but perpendicular to the ones you’ve already put on there. This means you can put a pot right on the stove. The pot will sit approx 1/4" to 3/8" off the can. I also made a small windscreen out of some old alu flashing, which curls up nicely to fit inside my pot.
I hope that makes sense. If not please tell me and i’ll post a picture on my photo site host. It works really well for me, maybe it will work for others too.
Cheers
P.S Has anyone else tried this?
Cheers