Those of you that are experiencing issues with LP fouling out injectors. You may do some research on the spark plugs that are being used.

I am almost certain that Hyster/Yale do not call out for 2 different spark plugs between gas and LP. GM is going to install plugs for gasoline application and LP needs to be one heat range hotter.

When I went to an Impco school many years ago, I had a discussion with the instructor on LP conversions from gas. As I was about to get multiple trucks from a customer that wanted to convert from gas to LP. He said that the plugs were important to change to a hotter heat range for thorough combustion.

I just dont know for sure if this stands true still for computer controlled systems, but I'm pretty sure it does.