Well I don't know what to do now. My wife calls me this morning, now that she is paying attention to rpm, saying it never seems to idle below 1000 rpm. She says it is still driving fine, and I believe her, but I am also thinking she is being nice about it as well.
So I'm kinda in the middle now, between I don't give a crap about it, and I know it wasn't doing this prior to repairs/cleaning. I drove it for a week during the bitter cold, and I didn't notice anything like this at all. I'm pretty anal about stuff like this so I notice the little out of the norm things more often than I care to admit.
Again, I could induce the situation with a on/off of the ac/heat system. I literally turned it on, watched it happen, hit "off" watched it go away a bunch of times. Could it be a bad IAC sensor? I think this is the sensor to the right of the throttle body that has a connector plugged into it? I did remove this connector when I did the throttle body cleaning, so maybe I messed it up somehow? Or could it be something to do with the sensor to the left that is on the tube connecting to the air cleaner?
Lets roll this back to the start.
Truck throwing codes of P0105 and P0128, on occasion clearing themselves, but always coming up, even after I cleared them. (prob for 6 months or more)
Monitored truck via torque app, to see coolant temp never reaching above 160F.
Removed battery (used memory saver), alternator, belt, T-stat and Coolant sensor. Replaced coolant sensor and t-stat with new, put back together.
Started truck, ran fine, idled right at 6-700 rpm. Ran it till it warmed up to 195F idling. Shut it down and called it a night.
Next day, removed throttle body that was severely gunked up and cleaned. Also replaced air cleaner with new. Reinstalled, reconnected all hoses, connectors, etc. Reset pcm via fuses for 15 min. Started up. Ran fine, sounded great actually, idled at 6-700 rpms. Cleared all codes via torque app at this time.
First drive, noticed high idle backing out of driveway and while driving. Didn't do a ton of stop and go. Came home, replaced upper radiator hose that appeared weak, "burped" the radiator that seemed to maybe have a air bubble in it. Pulled PCM fuses for 30-45 minutes. Turned key to on for 5 minutes, then started truck and let it idle without touching gas for 10 minutes, took it out for a forced stop and go drive for about 15 minutes through local subs. High idle seemed lower, still fluctuating idle but better. Shut truck off for a couple hours.
Same night, turned key to on for 5 min. then started truck and let idle without touching gas for 10 minutes. Took for a more extended drive of over an hour. Started with as much stop and go ans I could find lights for. In the middle a little highway cruising. At the end, more stop and go as I could find lights for. Again, high idle seems to be disappearing, still fluctuating but still feels better.
Next day, wife says seems to be driving fine. When I get home I start it, see the fluctuation, but also see it go away when I turn off AC. Can induce it on/off with ac/heat on/off. Try to blow smoke in areas of throttle body and vacuum lines, can't see anything "sucking in". Make sure again that all hoses and connectors are attached, they are and that nothing looks broken, it doesn't. Shut it down and call it good.
Today, wife is paying attention to rpms saying it seems to not want to idle below 1k rpms. I have a feeling I know what she is talking about, and its this situation. Truck idles up to 1-1200 rpms, then slowly idles down to 6-700 rpm, waits maybe 10-20 seconds then back up to 1-1200 rpms and back down. My feeling is she never sees it going lower because not enough stop and go for her into work and she doesn't have enough sitting time before she has to hit the throttle to go.
Thats all I got. It has yet to throw the codes again since my repairs. In the past I could clear the codes via the torque app and they would come right back the next drive cycle. Its been through probably 4 or 5 drive cycles since the last pcm reset. I suppose it could just be great timing that the ac clutch might be going out right when I did the repairs. I assume to get the belt completely off you have to thread it past the fan and shroud somehow? How long would it be safe to drive it like that? I mean the symptoms don't seem to appear as often until its on the road, so just idling it in the driveway I don't know if it would make any difference taking the belt off.
Any suggestions? Or should we just drive the damn thing as normal until something else shows up or the symptoms get worse?
Edit: Both times when pulling the pcm fuses I pulled 10 and 28. I think one was a 20 amp (yellow) and the other a 15 amp (blue) or maybe it was 10 amp. Either way both were labeled pcm on the fuse box. I have yet to do a complete battery pull.