Throttle Body Valve Adjusting?

[Gebo]

In the process of changing out the spark plugs on my '02 Toyota 3.4, I decided to do a little throttle body cleaning. Got my cleaner, sprayed a
little in the tube and proceeded to twist the throttle to "wide open" position. Seemed sorta weird in that the butterfly valve did not turn wide open. It only
opened about 1/2 way. I have noticed that when I floor it that it doesn't downshift like my other vehicles. When I mash accelerator to the floor,
shouldn't that butterfly valve be parallel to the surface of the earth?

 

[KrisZ]

Yeah, it should be all the way open. Did you manually modulate it or with the gas pedal?

 

[Gebo]

Yeah, it should be all the way open. Did you manually modulate it or with the gas pedal?

Manually. Would that give me false reading?

 

[KrisZ]

since you could only open it partially with a manual method, I think there is a hard stop somewhere or the gears are broken and are causing a jam.

If it opened partially with the gas pedal, that could be due to sensor failure or calibration issues, but would still open fully manually.

You may have a mechanical issue as I hardly doubt this is how far it normally opened up.

 

[Astro14]

If it has a cable to actuate it, there is a good chance that the cable is stretched, and out of adjustment. Get the FSM data on how to adjust the cable. If it has a transmission kick down cable (likely, if we’re talking about your 4 Runner), adjust that, too.

 

[Gebo]

Well, I gotta do some checking once my assistant gets home. LOL

Gotta be careful moving all that old plastic around...

 

[oggb]

The mechanical linkage/cable only opens the throttle body part way on some early drive by wire setups. Turn the ignition on/engine off and try again and it should open all the way like you'd expect.

 

[Gebo]

The mechanical linkage/cable only opens the throttle body part way on some early drive by wire setups. Turn the ignition on/engine off and try again and it should open all the way like you'd expect.

OK. I'll give it a try this evening. Thanks!

 

[Gebo]

Well, when we mash the accelerator to the floor, the throttle plate still only opens half way. What is my next step to try before I take it
to my mechanic? The accelerator cable is not slack. It is hanging up on something.

 

[Trav]

Disconnect the cable and make sure the throttle opens all the way, if it does look for the cable sheath being loose or off on one of the clamps or cable bracket. You can see them here..

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[Gebo]

Disconnect the cable and make sure the throttle opens all the way, if it does look for the cable sheath being loose or off on one of the clamps or cable bracket. You can see them here..

78180-35260 Genuine Toyota Cable Assy, Accelerator Control

ToyotaPartsDeal.com offers the great deal for genuine Toyota parts 78180-35260 (7818035260) Cable Assy, Accelerator Control for $105.00. All parts are backed by the Toyota's warranty.

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It will not open past half way with accel cable disconnected and my brute force on the black wheel. Pics are coming.

 

[Gebo]

I can turn the black plastic wheel almost a qtr turn before the valve even begins to move. 2nd pic is at rest. 1st pic is after I have
turned the wheel to the point the valve just starts to open.

 

[Gebo]

Wide open throttle pics

 

[KrisZ]

Gee I didn’t even think the throttle could be cable operated, I’m so used to everything having an electronic throttle body.

Still, looks like something internally is wrong. If you can turn it without the valve moving, then perhaps that plastic piece is worn where it connects to the shaft. It’s most likely keyed or has a flat somewhere to turn the shaft and maybe that is now worn to the point where there is a lot of play.

 

[meep]

Yep. No that’s not far enough. The mechanical style should certainly open full bore, or close to it. Some I’ve seen might be 7/8 to full but not perfectly, but certainly more than that.

in this arrangement, I’m pretty sure the throttle position sensor (tps) reads the position of the same throttle angle, which is why the transmission doesn’t kick down.

I would remove the TB and take the cover off the TPS. You should be able to find something mechanically blocking it.

 

[Gebo]

Thanks! I’m gonna try and slowly do some disassembly tomorrow. And take pics as I go.

 

[Gebo]

Yep. No that’s not far enough. The mechanical style should certainly open full bore, or close to it. Some I’ve seen might be 7/8 to full but not perfectly, but certainly more than that.

in this arrangement, I’m pretty sure the throttle position sensor (tps) reads the position of the same throttle angle, which is why the transmission doesn’t kick down.

I would remove the TB and take the cover off the TPS. You should be able to find something mechanically blocking it.

Makes perfect sense why there’s no kick down. Heck, it’s been this way for years.

 

[Trav]

I am not familiar with this throttle body but it seems to be some sort of oddball hybrid and only opens that far with the cable, electronic controls the rest. I remember GM having something similar years ago.
Check this out it appears to be the same as yours.

 

[Gebo]

Trav, the 2001 and 2002 I know have this hybrid system like in the video and it has perplexed many a 4Runner owner.
Apparently going back to 1999.

I found out about it in a 4Runner forum last night around midnight. It's a combo "drive by wire" and "electronic" set up. Five minutes ago, I got my wife to turn the ignition "on" and press accelerator to the floor and shazam! The throttle body opened wide open.

The way it is acting is perfectly normal. Now I gotta decide whether to clean it completely like the YouTube.

 

[Trav]

I would give it a good cleaning and forget it.