throttle and butterfly valve question

The 03 and 04 V6 have an accelerator pedal position sensor. It is some sort of potentiometer that controls the voltage to a throttle control motor located on the back side of the throttle body. It is the throttle control motor that opens and closes the butterfly valve in the throttle body. The cable in that picture is attached to the APPS. Like Hoss said, with the truck off, the mechanical part of the APPS will only open the butterfly valve after you pull the cable about 50% of the way. Try this, with the key in the "on" position, pull the throttle cable. The response of the butterfly valve should now follow how much you are pulling the cable. If you google "tacoma APPS", you will find many posts stating issues with intermitent acceleration problems pointing to the APPS. I've heard it best described as it feels like your foot sliding off the gas pedal. Good luck.

 

I took it to toyota in December and they couldn't figure out what was wrong with gas mileage.

I'll read up on that "apps". Thanks for your help.

 

is the tailpipe really sooty and black? Is your mpg around 13? If so you may have a failing Air Fuel Ratio sensor. Mine took a few months to fail and throw a CEL.

 

I think it might be sooty but il have to check on my break to be sure. It does have "smoke" or something you can see coming out of it. And it gets about that in gas milage. I use to get around 19 mpg.

I have ben reading some more on the forum and I found a better way to describe what the truck is doing. With my foot not moving staying at a constant speed my truck will stop responding but its so fast i can't get my eyes on the rpm's to see if its dropping. That and the strange exhaust and bad gas mileage.

 

As I recall every model since also has this, not just the 03 and 04 models.

I did some research to clarify what I thought was proper operation. I was wrong, the cable does go to the gas pedal, and is used to actuate the APPS as mentioned, and for "limp home" mode if the ASCD system fails. NYTaco is correct on testing procedure for the ASCD system.

 

Ok thank you all I'll be working on it this weekend I'll report back with what I find.

 

Ok need to know something. Called toyota this morning and price the tps and they tell me I that the 01-02 can just replace the tps but the 03-04 have to replace the ENTIRE THROTTLE BODY! Which is $1200 compaired to $60 for just the tps. So can I just get the tps and replace it? It would be nice if someone has done this on a 03 or 04 could tell me if it worked for them.

 

i would think you could but i am not sure

 

Yeah I know but what does everyone else say?

 

hey, that does sound strange, I replaced the one on mine a few months ago, (yes I have a granny truck). now I don't know this person, but have seen the ad on craigslist for a few months, don't know if it would help, but here it is,
http://chicago.craigslist.org/nwi/pts/3199205136.html

 

I sent the guy an email.

 

that is a strange problem but I'd be damned if I would spend 1200 on a new TB its a truck not F1.

 

I have heard the same thing as far as replacing just the TPS on an 03 or 04. Sorry that I can't confirm it though. I know the APPS and throttle control motor cannot be purchased from Toyota without buying the entire throttle body, but unsure of the TPS. Did you try visually watching the butterfly move with the key on? I'm sure that there is a testing procedure for the TPS with an ohm meter if you knew what the specs. for it were. No way in hell I'd buy a $1200 throttle body without knowing more.

 

I just checked it sounds like it is opening a soon as I turn the throttle switch. I'm in town about to eat so i can't take the income house off to see. I can't believe no one has replaced this on an 03 or 04.

 

Does anyone know the part number for the accelerator pedal position sensor? I googled it and it just comes up the tps and I can't find the part on a couple of part websites?

 

The APPS is not available by itself.

 

While the APPS is not available, the TPS sensor is, if that is what you are talking about replacing. Be aware that the APPS sensor and TPS sensor are two different parts. The APPS sensor is there to detect basically how far you have pressed the gas pedal, while the TPS measures the actual position of the throttle plate.

If the TPS sensor is what you need, you can find it at Rockauto.com for $42.79 plus shipping charges. The Rockauto part number is TH207

 

Update: cleaned the MAF sensor and so far so good. It hasn't stopped responding and its stopped the funky smell from the exhaust. Hope it will stay that way. Thanks to all of you fire your help.

 

Cool, hope it stays running well. It's always nice when it is something simple.

 

Yes it is.