High Idle After Cleaning Throttle Body 2001-2002

[D Farms]

So my 2002 has a different throttle body because its "drive by wire".

here is a description of how the throttle body works on my 2002. there is a cable that comes from the gas pedal, it attaches to the throttle body on the front, on the back there is a compartment that holds a motor and gear set, and attached to that gear set is the tps or throttle position sensor. there is no IAC, in fact the coolant just passes right through for some reason and is not connected to anything. the cable coming from the gas pedal can actuate the butterfly after overcoming a lot of slack, this is in case the tps fails or something.

so heres my problem, after cleaning all the grime out of the throttle body the idle is about 1200 rpm instead of the normal 600-700 rpm. I thoroughly cleaned the entire thing and there is no residue left over or liquid left. the tps sensor is adjustable but I left it in the position it was in when i removed the throttle body. there was a significant amount of grime so I cleaned it all, i also reset the efi. the feeling i get is that the tps needs to be adjusted because it feels like the idle is stronger while in drive.

update: I adjusted the angle of the tps sensor, and was able to correct my idle speed. to me this indicates that idle is not always dictated by the ecu, there is a screw that basically sets the idle speed just like a mechanical throttle body. anyways if you have the drive by wire throttle body and have this problem, simply adjust the tps sensor angle, I loosened both screws and then rotated it until the idle was where I wanted while it was running. this should help someone as I havent found any other info on the subject.

 

[beliboy32]

so here is my issue ive cleaned it and same thing however the butterfly isnt opening fully when i pull the cable. Itried adjusting the spring but that did nothing any ideas?

 

[nc-grayson]

Clean the IAC.

Edit: just read 2002. I can't read. Sorry.

 

[anniesball72]

So my 2002 has a different throttle body because its "drive by wire".

here is a description of how the throttle body works on my 2002. there is a cable that comes from the gas pedal, it attaches to the throttle body on the front, on the back there is a compartment that holds a motor and gear set, and attached to that gear set is the tps or throttle position sensor. there is no IAC, in fact the coolant just passes right through for some reason and is not connected to anything. the cable coming from the gas pedal can actuate the butterfly after overcoming a lot of slack, this is in case the tps fails or something.

so heres my problem, after cleaning all the grime out of the throttle body the idle is about 1200 rpm instead of the normal 600-700 rpm. I thoroughly cleaned the entire thing and there is no residue left over or liquid left. the tps sensor is adjustable but I left it in the position it was in when i removed the throttle body. there was a significant amount of grime so I cleaned it all, i also reset the efi. the feeling i get is that the tps needs to be adjusted because it feels like the idle is stronger while in drive.

update: I adjusted the angle of the tps sensor, and was able to correct my idle speed. to me this indicates that idle is not always dictated by the ecu, there is a screw that basically sets the idle speed just like a mechanical throttle body. anyways if you have the drive by wire throttle body and have this problem, simply adjust the tps sensor angle, I loosened both screws and then rotated it until the idle was where I wanted while it was running. this should help someone as I havent found any other info on the subject.

I didn't realize this and had my mechanic remove the Throttle Body on my 02 and clean it. I don't think he realized this either until he took it off.

Bottom line he cleaned it somehow. Now my cold start idle ( after sitting all night) is 1900 rpm. After awhile it comes down to 900 rpm. I have tapped on the throttle body during high idle with no change.

In my mind I shouldn't have to adjust the tps sensor angle since it does eventually come down.

What do you suggest. Remove and clean again?

 

[anniesball72]

Bump.

What have other 2001-2002 4Runners or 2003-2004 Taco owners done in this situation to remedy?

I have also searched Tacoma World to no avail.

 

[nissanh]

You have fly-by-wire throttle control.
You do not need to do anything, just continue to drive and it will relearn on its own. My friend's 06 Corolla in Australia had the same issue and he said after 2-3 days of driving, the RPM returned to normal.

 

[jgue467]

Bump.

What have other 2001-2002 4Runners or 2003-2004 Taco owners done in this situation to remedy?

I simply bent the 'L' bracket holding the cable end while the engine was fully warmed/idling until it was where I wanted. Starts cold and idles around 1300 and drops steadily to 700 as it warms up.

Crude as heck yet it works on mine....

 

[negusm]

You have fly-by-wire throttle control.
You do not need to do anything, just continue to drive and it will relearn on its own. My friend's 06 Corolla in Australia had the same issue and he said after 2-3 days of driving, the RPM returned to normal.

EXACTLY THIS.

Idle will be erradic for up to a WEEK. Then it will settle in and be solid. This was after I replaced my entire TB with a new unit.

Do not bend/twist/adjust anything.

-Mike

 

[anniesball72]

EXACTLY THIS.

Idle will be erradic for up to a WEEK. Then it will settle in and be solid. This was after I replaced my entire TB with a new unit.

Do not bend/twist/adjust anything.

-Mike

I couldn't agree more. It has been almost 2 weeks and it seems to be settling down.

Can someone explain why this happens? If there is no IAC to clean what has changed in the ECM's "eyes"?

So all I can figure that my mechanic cleaned was the bore of the throttle body and what's behind the metal plate on top. Right?

 

[anniesball72]

EXACTLY THIS.

Idle will be erradic for up to a WEEK. Then it will settle in and be solid. This was after I replaced my entire TB with a new unit.

Do not bend/twist/adjust anything.

-Mike

Update was still having the same high idle problem so I reset the computer again. Left the battery cable off a few hours yesterday.
Re-connected it. Started up cold fine and idled fine.

This morning. Started it up and it did not high idle. I idled about 1300 for a few minutes then settled down. I thought I was through the tunnel!

Drove it around town a little 2-3 miles, barely warmed up. Stopped at the grocery store stopped and restarted the truck. Now it started idling very low. Like 4-500rpm.

Reved it a little no help. Restarted truck no help.

Drove on the highway about 5 miles, got off off ramp and the pedal went dead, no throttle. Check engine light came on. Engine would only rev if I used the failsafe cable.

Restarted truck at off ramp throttle came back. would run.

Next intersection same thing had to restart it.

I scanned the ECM and it had a P2111 code. Throttle stuck open.

I cleared the code. Restarted and it seemed fine including idle.

The above sequence is exactly what happened right after I had the throttle body cleaned. Does that mean it's on it's way out?

 

[negusm]

Well, I don't know but it could be a few things with the TB.

Are you sure P2111 is "Throttle stuck open". The description I get from google is "throttle actuator control system stuck open". The difference is subtle.

P2111 Throttle Actuator Control System Stuck Open

I would imagine that code is probably either:

TPS
Pedal Position Sensor.
Internal motor.

They are supposed to work in conjunction with each other.

Since now you can get the TPS from Partsgeek...for $40. I'd probably try that route first before plunking down for a full TB.

If that doesn't work, I'd also take the TB off, clean it really well inside and out again...and lube it. If it's busted...can't get any worse from another cleaning.

-Mike

 

[coil4866]

[MENTION=100116]D Farms[/MENTION] , if you're still on this forum, just wanted to send my thanks for this post! Like you, I didn't see any info elsewhere about the manual idle adjustment on the 01-02 4runner.

Note for others in the future: the screws are really hard to access while the TB is connected. What I ended up doing was making the adjustment as per the original post, then once I found the correct positioning I tightened the top one with one of these, as much as I could, then I disassembled the TB again and tightened the bottom one with a regular screwdriver.

Also worth noting that the OEM screws were stripped, so I replaced them each with:
- M4x0.70 16mm screw (with Philips head for less chance of stripping)
- M4x0.70 hex nut
- 4mm washer

The OEM screw seems to be something like 13-14mm which I couldn't find in the hardware store, so I just opted to artificially "shorten" the 16mm instead.

---

You have fly-by-wire throttle control.
You do not need to do anything, just continue to drive and it will relearn on its own. My friend's 06 Corolla in Australia had the same issue and he said after 2-3 days of driving, the RPM returned to normal.

Incorrect, at least in my case. I drove around for weeks with the high idle, disconnecting the battery several times to allow for idle relearn procedure. The only thing that addressed the issue was the manual adjustment as described by OP here.