I just bought an 87 F-250 6.9 (with a Banks turbo kit installed) and drove it home 3 hours with no issues, but as soon as I pulled up in front of my house and shifted into neutral the idle started climbing higher and higher until I shut it off. It did this a couple more times then I started it again a bit later and it seemed normal. My old Mercedes 300SD did this exact thing and it was a failed injection pump (as far as I know, I never figured out exactly what was wrong but swapping in a good used pump was enough to get it to work fine for several more years and it ran fine when I sold it). Obviously it's not acceptable for it to keep doing that, but does anyone have any troubleshooting suggestions? Do I need to swap the injection pump before I drive it anymore?