TA_Freak

Happy New Year! The TA was dead as a door **** this morning after sitting in the cold for 5 days. Once cranked, it wanted to idle high. I figured there was some relearning going on. However 20 miles down the road she was at 2k when I popped it into neutral while on the highway. It acted like the cruise was stuck as I was using it.
Once I reached my destination, it slowly settled into the idle which is set to 775 rpm.

I took a gander under the hood and didn't see anything obvious; I figure I'll clean the throttle body and MAF later.

Any ideas?

Y2K_Frenzy

Idle air control valve??

TA_Freak

Thats a possibility. Interestingly, it’s fine after another 20 mile drive.

RPM WS6

iTrader: (3)

I don't think there's any actual issue here.

Skipping the idle relearn procedure isn't a big deal on a stock car, but it looks like the OP has a bunch of mods that would require custom tuning. The idle will eventually relearn on it's own regardless, as seen above, but in my experience the process can be a bit more dramatic with an aftermarket cam & tune - especially if you don't do the suggested OBD relearn (which involves several minutes of uninterrupted idling, in gear and out, after operating temp is reached - and then a restart of the engine).

Assuming you don't see any further problems, I wouldn't give this another thought (meaning, I wouldn't go looking for a problem because, so far, it doesn't really sound like there is any problem in the first place).

The only actual "problem" that I see here is your battery dying after just 5 days. I live in a much colder climate, and I have a spare daily driver that often sits for 2-3 weeks at a time in the winter. The battery will still have plenty of power to fire the engine even after 3 weeks of being untouched in cold weather. So I suspect that you either have an old/weak battery or some sort of excessive drain.

TA_Freak

Good points. Time to break out the ammeter to see if there is some parasitic draw of current. I have an optima red top battery that's only a few years old.
The idle returned to normal eventually yesterday; it was actually more than the idle speed as the engine was racing at 2k on the highway when I popped it into neutral.
I had thought about reflashing the tune.

Y2K_Frenzy

That’s why I was thinking maybe the IAC. If too much air is going through it (stuck open) it can cause the revs to hang and or be slow to fall. That’s how it is on another car I have anyway. I’m assuming the LS would be the same.

TA_Freak

Definitely has the symptom of that. Not sure how long those are supposed to last, but it's been steady busy for the last 23 years and 398000 miles!

RPM WS6

iTrader: (3)

It would be odd for an IAC to fail at the exact same moment that the battery died. Not impossible, but the odds are doubtful. Again, lots more weird things can happen (this includes shifting into neutral even at speed) with improper idle relearn when the car has a cam and tuning.

With that in mind, it's also possible that the IAC is not in the best of health at this point, but "seemed" to be fine until the forced relearn of a dead battery caused some freakout and exposed some weakness. In other words, maybe an early warning sign. But I still wouldn't mess with it unless the problem returns without the battery dying or anything else to prompt any weirdness.

The newer Optima batteries are not nearly as good as the older generations; quality is not what it once was with this brand. Based on this, probably you don't have any issues with excessive drain but just a bad battery.

01ssreda4

iTrader: (96)

Nothing wrong here. And will likely do it again next time the battery goes dead.

TA_Freak

Interestingly, my Optima red top was dead last night. Charged it overnight and didn't have any issues.

Y2K_Frenzy

Time for a Walmart Everstart..

TA_Freak

That what I hear. I've got three of those red tops and one is dead after smoking it - charging. The other 2 are iffy in the cold. When the TA's gauges peg hard right when I crank it, I know it's low.

TA_Freak

Not even related. The red top has died a few more times with the colder weather.

This morning by revs were hanging up at about the same spot as twice before. I'm thinking IAC time. It's happened twice since I posted the start of this thread.

Y2K_Frenzy

Take it off and clean it with something like this first. I use this to clean and lube guns etc and it works well. I’ve also used it on an IAC. It’s safe for plastics, gunk will run out, and it’ll lube the spring. all-in-one RV

TA_Freak

No such luck. I cleaned it and it still idling high and stumbling low at times. The plunger had a slight tear near the base of it. I just ordered one.

Y2K_Frenzy

Darn it. Well I hope the new one does the trick for you. Surely maybe it will.

TA_Freak

I'm golden! The new valve did the trick. After knowing it was good, I went ahead and cleaned the MAF and throttle body. I did want to do it all at once, or I would forever wonder what fixed it!

Y2K_Frenzy

Atta boy.