Unique Idle in gear
I have talked to as many people as I can about this but no one seems to know why it is doing it. Since the trans was rebuilt my 2001 7.3L has had a very unique idle while in gear after heating up a bit. It idles normal when the engine is cold in the mornings or on a cool day but if its hot out and I'm doing a lot of city driving it starts to do it. The idle jumps from 700-1000 roughly, it sits on the lower RPM for about 3 seconds then jumps up to 1000 and falls back down to 700 and repeats, if I take off when the RPMs are that low its really sluggish but a little bit of throttle pulls it out quick, it has never died doing this and while it is doing it if I pop it out of gear into N it idles like normal. I took it back to the shop that rebuilt the tranny and they said its nothing to do with the trans because if you put it into low/1 it still does it.
I don't have any gauges on it yet but should get my Edge Attitude monitor this weekend. I ran some Lucas Injector cleaner through the truck last tank and it seemed to mellow it down a little but did not get rid of it.