What do you mean goes out? Take the glow plug out and inspect, the coil should look like a perfect spring with verry little buildup,buy yourself a couple os long reach mediums, make sure the igniter is always charged
I'll start it and run it. When I try to start it again it won't start. I used 3 plugs today trying to figure it out. When I pull the plug out its almost black
I had a plane do this to me. Drove me nuts. Found out that I had three things wrong. First the wrong glow plug for the engine, second the wrong fuel mix (way to rich) and third I was using a power panel glow pug lighter that was sending to much power to the glow plug.
This sounds like one of the first two, or a combination. Hope this helps, Shaun