Powermax 45 won’t cut through metal

My PM45 won’t cut through 16 gauge steel at regular speeds. It fires, but cuts half way through and blows slag all over the place. You just get an 1/8” wide melted grove in the metal. It’s at the right height. Not like the nozzle is a 1/4” off the metal.

If I slow it down to something ridiculous like 30 inches per minute, it will cut through, but of course it’s a terrible cut and eats nozzles.

Any ideas what cause that sounds like?

I’ve stripped the cutter’s ground wire back at the end to fresh wire and clamped that directly to the metal with vice grips. That didn’t change anything. I have air pressure and a new filter. Air should be clean and dry.