I just pulled up for a night of truck washing with two guys on the clock and one of my machines sounds like it’s turbo charged. Rpms are really high I think. It was misfiring last week so this morning I changed the oil and put new spark plugs in. Tested it and it ran fine. Problem just started when I got out to the job site.
So far I tried putting the old spark plugs back in but that did nothing.
Any ideas of something I can do to fix it in the field?