High Idle

So, about a week ago I changed my plugs and cleaned the throttle body. I have the 6sp manual, and prior to that my truck would idle at around 1200rpm on startup, then after a few minutes drop to 1k, then down to 750. And its always been like that ever since I bought it brand new.

On startup it now idles at 15-1600rpm and takes at least 5 min or so to drop to 12k. Heres the kicker, I used to be able to coast in neutral(for whatever reason) and the rpms would drop to 750. After the plug change and throttle body clean it will drop to around 1100 then climb up to 1400 while coasting in neutral until I come to a stop then it will drop to 750.

I changed my plugs the first time at around 40k miles. No problems. And now a plug change at 90k miles and a throttle body clean(which was pretty dirty btw).

Tried this at post #2, but no success
http://www.tacomaworld.com/forum/2nd-gen-tacomas/133106-cleaned-tb-now-high-idle.html

Sorry for the long post. Any ideas of what it could be?


A little something for reading this far

 

Last time I had a high idle issue it wanted to idle at 2k rpm every time the clutch went down. I let it sit and idle for 10 minutes after reset and it still took a couple days to straighten out.

FWIW my truck starts at 1500 rpm cold, takes about 3 minutes to get down to 1100. Idle when coasting in neutral is all over the map, sometimes it'll go down to 900 rpm, sometimes it'll stay up at 1500 even when warm and I'll have to throw it in 6th to drag the iMPG meter back up.

I've NEVER been able to get it down to 800 rpm or less coasting in neutral. I wish I could, it would drop fuel usage from 0.6gph to about 0.4

BTW thanks to your baitpic I had to read from the bottom up!

 

Ive changed the plugs before with no problem at all. Im thinking it has something to do with the throttle body, since i had it off and was manipulating the throttle plate to get it cleaned. I hope I didnt screw it up

 

The throttle body and butterfly get carbon buildup.
To compensate, the ECU opens the butterfly a little more to maintain idle.

When you clean it, the butterfly is suddenly open too far.
Eventually, the ECU will compensate and bring the idle back down... but it shouldn't take too long. I think my '03 Tundra normalized within a few days.

Might try disconnecting the battery to reboot the ECU.

 

Tried that, didnt do anything. Thanks tho.

 

It takes a ridiculously long time for this ECU to learn anything. It's not a 10-minute-educated smart Honda computer. This is Toyota. They have procedures. Think 500 miles-- and it still might be working on it.

For this reason I dread disconnecting the battery.

 

Thanks. I guess I'll just wait it out and see what happens. Unless someone else has any other insight on this.

 

Bump for the pinup pic! GL man I woulda figured the battery disconnect would have fixed the problem.

 

What's this thread about? I got?..... side ........tracked

 

Snap out of it lol!

 

throttle position sensor

 

Care to elaborate on this? The TPS is a sealed unit.

 

I highly doubt it's the TPS.

Unfortunately what the OP's truck is doing now is actually the normal behavior. I'm guessing yota did that to make the thing easier to downshift. Idling at 750 going anything over 10 mph is a real fluke.

Now if anyone can figure out how to "break" it again, I wanna know. That low in-motion idle would be nice for mpgs

 

I've noticed that if you coast in neutral, it will never drop below the fast idle RPM until your MPH drops low enough because it's anticipating being put back into gear and not coming to a stop, it just hangs there forever. I'm not saying you're driving any differently now than before, it's just an observation ...

 

Wouldnt it be nice if the truck let us do all the driving and choose what type of shifting we want? I dont miss my manual mainly for that reason^^^^

 

Eats up a good amount of fuel.

 

so whats the verdict on this subject,because I'm having the same exact problem with my 2000 tacoma and can not figure it out. its been like 1500 miles and tried everything and high idle is still there not to mention when i push in the clutch pedal while coasting the idle goes up and down 1100-1800 or just sticks at 2000rpm

 

nofx230, you have a different system. The 2000 Taco was still cable controlled throttle. What you describe sounds exactly like some kind of air leak. It most likely is a vacuum line (or a plastic 'T') somewhere with a crack in it.

 

Update: About 1000 miles later and still no change. Still idling high

 

I suppose the first thing I'd check is whether there's any dislodged gunk from your cleaning that's holding the throttle plate a wee bit open.