Stuck High Idle

One for the gauge and one for the ecm.

 

That throttle body looks like it's screwed up, not only is it off center but it hardly looks like it's the right size plate, Ive never seen one with a gap like that, when I had my 2.7 ive cleaned my throttle body cause it had a rough idle, but it was perfectly sealed there was zero gap on the side, maybe you should try to recenter the place and make it sit flush in the throttle body I'm guessing your valves are all good and nothing wrong but your throttle plate is letting extra air in the engine

 

Look at LCE.
They reworked my TB and did a great job.

Good luck.

 

No, the valve is fully closed. It has some play side to side if you pull on the bell crank that the throttle cable attaches to. One of the plastic pieces is loose inside of the tension spring, i'm wondering if that may have broken, i'm not sure how I would shim that thing to get it to center up.
Im going to go check out some used throttle bodies today and compare them to the one i've got, we'll see where that goes.

 

my 01 4 cyl did the same high idle but only after I put the new motor in. I assumed that the new motor had more airflow as it didnt have 375k miles on it... I noticed the same play in the TB and a wrecking yard TB with less play fixed the issue.

 

That throttle plate does look wonky, but don't forget to check for an ordinary vacuum leak.

 

Any new updates?

 

Alright everybody, a little update here
Ive been out at work for the last two weeks. So before I went to work I returned the IAC that I had bought from Autozone and ordered an OEM IAC from Rock Auto. In the interim I reinstalled the old IAC and I noticed a couple differences between the old IAC and the new one.
Old IAC:
1. The idle did not fluctuate and after a couple days settled down at about 1,150 RPM
2. The idle would run away with this one and revving the engine would make it settle back down, which is the reason I started this whole process in the first place. So no surprise there.
New IAC:
When I start the truck cold the idle starts off around 800 RPM and then as the it warms up the idle gets higher and settles out around 1900 RPM. If Im driving and I shift into neutral the RPM will flucuate, dropping to about 1100 and revving back up to 1900 and fluctuating back and forth about 5 times before settling at the higher RPM.
Im guessing this is the ECM trying to figure the new IAC out. Im going to drive it for a couple days and see if it starts to get back to normal.

 

Start with the simple stuff. This sounds like a vacuum leak. Sometimes when I get stuck on a problem, I get tunnel vision and I get focused on one thing and I ignore the other things it could be. Grab the ends of all your vacuum lines, twist and pull. Are they loose? Are they cracked? There are a few lines on the driver's side that are under the manifold. Check them.

 

That's weird, my idle does the exact opposite. It starts high around 1500 until the engine gets up to operating temp and then slowly drops to about 900.

 

I believe this is normal behavior. My truck does the same since the day 1. BTW mine is manual transmission.

 

Deja vu!

I initially got a IAC code years ago, decided to clean it, the TB, and MAF. Reassembled and got the exact symptoms you are experiencing. I (like an idiot), threw a new IAC, MAF, TPS, and even a ECU at it as I was getting some weird readings on one of the sensors, and the toyota manual said it could be the ECU. I spent hours trying different adjustments on the IAC, and TPS, and finally realized my TB looked like yours. It was cleaning it that allowed more air through. So I replaced the TB with a used unit that worked great for around 3 years, then that one started to experience the same issue. So, again, I replaced it.

I have a manual trans, and while the manual trans TB has a dash pot, my newest replacement does NOT, and it doesn't seem to affect anything either which way.

 

there is a YouTube video where a guy took the throttle cable brackets ande return springs off and added a thin washer and reassembled it to solve his issue. Not having actually done this I would be concerened with trying to tighten up the play too much and having the throttle stick.

 

Same here, manual. I thought something was wrong with it so last week when I changed the air filter I took the air box and intake hose completely off and cleaned the throttle body and MAF sensor. I wanted to clean the IAC valve, but I didn't have the best tools on hand and was afraid I was going to damage my vacuum hoses trying to pull them off. Those fuckers were tight as hell. Anyway, after putting it all back together it does the same as before, though cleaning the throttle body seems to have knocked down the warm idle from 1k to 900 or so. I bet that when I clean the IAC it will come down closer to 750 rpm.

Does yours jump to 1900 rpm as soon as you take it out of gear to stop at a red light?

 

Sorry about the slow response fellas! I didn't get an email saying there was a response, which I thought was weird. Low and behold!

I do not think it's a vacuum leak, as I've triple checked all the vacuum lines and they are all sound. Even blew all of them out to make sure some gunk didn't get stuck in there.

I've been driving it for 3 days now and no change on the high idle. I'm heading down to Oregon for a few days tomorrow so I'm going to disconnect the battery and let it sit for three days and see if that results in any change.

Other than that I've seen posts and videos where people add a shim to the throttle body, but that's with the older style throttle body. They changed it in 2001. The 2.7 as well was only this way from 01-04 so it's a narrow range to find a new throttle body.
In addition there's play on both side of the valve, so I don't think shimming it would fix the problem.

On the off chance that I didn't fully reset the ECM I'm going to see if there's any change in a few days. I'm also going to check some salvage yards in oregon and see if they have my TB. If there's no change swapping the TB will be my next stop

 

The idle starts to bob, goes initially to about 1,200 and the fluctuates up and down from 1200-1900. Then stabilizes at 1900.
The reason I don't think it's a vacuum problem is I reinstalled the old IAC and that one just sat at 1100. Still high but it didn't have any of the fluctuations the new ones have had. Not really sure why the new ones do that. Hopefully resetting the ECM will do it!

 

Watching this thread with curiosity. I'm having similar symptoms on my rig after cleaning the throttle body and idle air control. I reset the ECM and after a week my idle was down about 750-800rpm. However, it's now climbed back up to 1500-1800rpm even when the engine is warm.

 

Ok So A little update here...still having the issue.

After letting the ECM reset for a few days I think I have about 5-7 days of driving on the new IAC and still no change. Yesterday while driving the CEL came on with two codes: P0505, which is an IAC Malfunction and a P0420 which is a catalyst system efficiency below threshold bank 1. Its got to be the throttle body, ive read a couple similar threads to my situation and it seems to be the fix.

As far as the P0420 ill prob just put some fuel system cleaner in this next tank and see if it goes away. I dont use gas with Ethanol, so most likely its just something weird associated with all these issues im having.

Anybody have any recommendations on where to find a Throttle Body for a 2002 2.7L? Ive been having a tough time tracking one down...

 

@Speedytech7
@mechanicjon

 

I'd try cleaning the IAC and getting a new gasket for it. They come off the throttle body as a separate part.