Good morning all, first post long time lurker. I just have to say I appreciate all that you guys do on this site and it has made life a lot easier for many of us.

So I got a new to me truck 1989 F250 460 C6 4x4. She's awesome. So its been a long ride of tons of repairs in hack wiring, heater core, frozen distributor, exhaust, vacuum leaks, and the list goes on. But I have it running really good except for the idle. Its strange. Hit or miss, high or low. So I unplugged the IAC (after cleaning it thoroughly along with the throttle body) and nothing happens. Engine warm or cold if I unplug it nothing changes. So I chased down vacuum leaks and fixed them and pulled codes. Maybe I'm a tard but I'm not gathering the codes correctly. Maybe its hard for me to count over 1 so I took a video and posted it. If anyone would could watch it I'd deeply appreciate it.

Thank y'all again for all of this, and as I peel through this truck I'll be posting answers that I have for the next guy. Thanks again!


Video link:

 

Looks like KOEO Code 11 (System Pass) and Continuous Memory (CM) Code 11 (System Pass).

If the idle does not drop down or stall the engine when disconnecting the IAC then you either have a vacuum leak, stuck IAC or someone has jacked with the Idle Stop Screw. Sounds like the latter to me. Take a look for signs of tampering. The factory used a bit of blue Loctite on the threads, take a look to see if someone has turned that screw at all.

One other possibility is a very worn throttlebody. Start with the screw inspection first.


Welcome to FTE!

 

Thanks! Thats what I figured but wasn't sure. As of an hour ago I hit the highway and tried the cruise control for the first time. It was sketchy at best… all over the place between a coast to tromping the gas so I cut it of. I'm guessing vacuum leak in there or somewhere. The TB was really nice after I cleaned the soot out of it. It was pretty fouled up. I'm headed out to the shop to check the screw and the cruise diaphram