High idle after cleaning throttle body

T

theirare

New member
Howdy folks,

Last weekend, my 2001 started sputtering at low speeds (in traffic and rolling to a stop) and then shutting off. I ran a scan and it threw a few codes: p0300, p0301, p0302, p0306

I was having MAF sensor issues, so I got a brand new one and installed it. I also changed plugs, wires, and coilpacks. And I also thoroughly cleaned the throttle body.

I'm now getting the same cylinder codes (p0300, p0301, p0302, p0306), but now also getting a p0120 and p1120 code.

The engine is not sputtering, but I do have a high idle of around 1600 RPM.

I removed the leads from the battery and let it sit for a few hours. Restarted the engine and it was still having the same problem.

For a little background, when I removed the throttle body for cleaning, I also unscrewed the throttle position sensor (I know I shouldn't have touched the painted screws). Now I'm thinking that this high idle problem is somehow connected to my throttle position sensor adjustment, and now I'm wondering how to fix it.

Should I just get a new TPS or is there some trick to installing it and positioning it correctly? What tools do I need for the job?

My 4Runner and I thank you in advance for your help!
 
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theirare said:
Howdy folks,

Last weekend, my 2001 started sputtering at low speeds (in traffic and rolling to a stop) and then shutting off. I ran a scan and it threw a few codes: p0300, p0301, p0302, p0306

I was having MAF sensor issues, so I got a brand new one and installed it. I also changed plugs, wires, and coilpacks. And I also thoroughly cleaned the throttle body.

I'm now getting the same cylinder codes (p0300, p0301, p0302, p0306), but now also getting a p0120 and p1120 code.

The engine is not sputtering, but I do have a high idle of around 1600 RPM.

I removed the leads from the battery and let it sit for a few hours. Restarted the engine and it was still having the same problem.

For a little background, when I removed the throttle body for cleaning, I also unscrewed the throttle position sensor (I know I shouldn't have touched the painted screws). Now I'm thinking that this high idle problem is somehow connected to my throttle position sensor adjustment, and now I'm wondering how to fix it.

Should I just get a new TPS or is there some trick to installing it and positioning it correctly? What tools do I need for the job?

My 4Runner and I thank you in advance for your help!
Click to expand...

Not sure on all your cels but the high idle is most likely the IAC. It's on the bottom with the vacuum lines going to it. Gunk gets in there when cleaning. Take a wrench and tap on the housing of the IAC when running and it should dislodged the junk and idle should go back to normal.
 
You can also shoot some throttle body cleaner in the IAC's bypass port and flush it clean. If that was the problem you'll know soon enough. Look for a vacuum leak also.


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JayRolla said:
Not sure on all your cels but the high idle is most likely the IAC. It's on the bottom with the vacuum lines going to it. Gunk gets in there when cleaning. Take a wrench and tap on the housing of the IAC when running and it should dislodged the junk and idle should go back to normal.
Click to expand...

I already took the throttle body off and thoroughly cleaned it, including what I think is the IAC (on my 01, it's a metal plate on top of the throttle body with holes that go down into the main part of the throttle body). Anyway, I unscrewed that plate and cleaned the gunk out of each hole with a thin piece of metal. I cleaned all the dirt from the inside metal parts of the throttle body with throttle body cleaner.

My mistake was that I ignored the painted screws and took off the TPS sensor from the throttle body and now I can't seem to get it to adjust properly. The screws have elongated holes, which allows the position of the TPS sensor to be adjusted. Now, I think I just can't seem to get the angle right.

If I loosen the screws on the TPS sensor so that I can move it up and down about a 1/4 inch or less, then start the engine, then I can adjust it while the engine is on and hear the RPMs going up or down as the TPS sensor is moved. I can get the sensor to read about 800-900 RPMs while the car is running, but then in the process of tightening the screws down, it seems to move just enough to give me a rough idle. Now, I'm hovering between 500-600 RPMs when in idle.

At speed, there is no problem. But low speeds the idle is rough.

To make matters weirder, I unhooked my battery to reset codes and now my TPS sensor code is gone, but I've still got the p0300, p0301, p0302, and p0306.

I think my next step is going to be replacing the fuel injectors, but I'm trying to avoid that because the problem arose when I started fooling with the TPS sensor.

The truck also has almost 190K on it.
 
19963.4lsr5 said:
You can also shoot some throttle body cleaner in the IAC's bypass port and flush it clean. If that was the problem you'll know soon enough. Look for a vacuum leak also.


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Click to expand...

What is the best way to go about diagnosing a vacuum leak there?

Has anyone here just replaced all of their vacuum lines? If so, what is the cost and how long did it take?
 
Misfire on all cylinders now...

Adjusted the TPS sensor position again to get my resting idle down to 900-1000 RPMs.

Drove the truck around a bit, and it's very sluggish at low speeds (0-7mph) and feels like it wants to die.

Ran another scan and now I'm showing seven codes (p0300-p0306). It feels fine when revving up and traveling above about 10mph. I will get my bluetooth scanner in the mail tomorrow so that I can gather more detailed information.

What do y'all think?

Remember, I just replaced all the plugs, wires, and coilpacks. Also replaced the MAF for a different code that is now gone and I cleaned the throttle body GOOD.

I keep doing research, and one person tried a new PCV valve. I don't remember the last time mine was changed, so it's probably time for a new one. The hose connecting to the PCV is also a little cracked right where it connects to the PCV. Any ideas on if this might be the issue or where I can get that perfectly curved PCV hose from? Could I just try and wrap the ends of the hose with with electrical tape after replacing the PCV and the grommet?
 
What do y'all think?
Click to expand...

SEARCH! Here's how ---> http://www.toyota-4runner.org/3rd-g...te-search-toyota-4runner-3rd-gen-section.html

Some advice in this thread, more below. Mostly it seems to boil down to the IAC likely got some cleaner/gunk in during the cleaning OR hoses not fully & properly reconnected.
--> http://www.toyota-4runner.org/3rd-gen-t4rs/104546-high-idle-idle-after-cleaning-throttle-body.html

I replaced my IAC and complete TB for less than $150 in parts a few years ago. Bought a low miles used one on ebay with warranty and everything. IAC problems (never threw a code) were all solved.

Also see:
---> http://www.toyota-4runner.org/3rd-gen-t4rs/198674-unusual-idle-after-cleaning-maf-throttle-body.html
---> http://www.toyota-4runner.org/3rd-gen-t4rs/123396-my-high-idle-cured.html
---> http://www.toyota-4runner.org/3rd-gen-t4rs/187399-high-idle-2k-rpms-need-help.html
---> http://www.toyota-4runner.org/3rd-gen-t4rs/103745-worn-throttle-body-causing-high-idle.html


:bat:
 
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19963.4lsr5 said:
Your entire missfire issue could be low fuel pressure.


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Click to expand...

Could a dirty fuel filter cause low fuel pressure? What else might it be?

I want to try and save replacing the fuel injectors for last if possible because I can't get them shipped directly to California, where my truck is right now.

Thanks again for all the help. Have been trying to search and troubleshoot based on the posts in this thread, but I'm still having the misfire on all cylinders and a high idle (about 1300-1400 after it's warmed up).

I'm now learning how to use Torque Pro to see if I can get more detailed information out of it.
 
theirare said:
Adjusted the TPS sensor position again to get my resting idle down to 900-1000 RPMs.

Drove the truck around a bit, and it's very sluggish at low speeds (0-7mph) and feels like it wants to die.

Ran another scan and now I'm showing seven codes (p0300-p0306). It feels fine when revving up and traveling above about 10mph. I will get my bluetooth scanner in the mail tomorrow so that I can gather more detailed information.

What do y'all think?

Remember, I just replaced all the plugs, wires, and coilpacks. Also replaced the MAF for a different code that is now gone and I cleaned the throttle body GOOD.

I keep doing research, and one person tried a new PCV valve. I don't remember the last time mine was changed, so it's probably time for a new one. The hose connecting to the PCV is also a little cracked right where it connects to the PCV. Any ideas on if this might be the issue or where I can get that perfectly curved PCV hose from? Could I just try and wrap the ends of the hose with with electrical tape after replacing the PCV and the grommet?
Click to expand...

You are on the right track. It's dying when you give it a little gas because the TPS is overadjusted the other way. The throttle is opening but the TPS is not registering it, so it sputters and wants to die because there is no fuel. So yes, it's low fuel and all that but because of the TPS being out of position.

Adjust the TPS back a little. It's going to take a half-dozen tries to get it right, but it's possible.

Also, the IAC is on the bottom of the throttle body, not the top.

P.S. You're not supposed to remove the screws to the TPS but you know that now :)
 
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I had IAC issues for a year, sometimes the truck died and wouldn't start for a few minutes. It never once threw a code.
 
gamefreakgc said:
You are on the right track. It's dying when you give it a little gas because the TPS is overadjusted the other way. The throttle is opening but the TPS is not registering it, so it sputters and wants to die because there is no fuel. So yes, it's low fuel and all that but because of the TPS being out of position.

Adjust the TPS back a little. It's going to take a half-dozen tries to get it right, but it's possible.

Also, the IAC is on the bottom of the throttle body, not the top.

P.S. You're not supposed to remove the screws to the TPS but you know that now :)
Click to expand...


Tried adjusting it while watching the RPMs in Torque Pro today and it didn't really work. When I get it down to the 600-700 RPM range, the engine will periodically shudder and threaten to stall.

When I got under the truck to inspect the fuel filter, now I feel like I'm hearing a high pitched whine coming from an unknown location. Maybe it's a vacuum line?

The solutions I have left to try are:

1. replace fuel filter (need to purchase some flare wrenches for this one)

2. replace fuel injectors

3. replace the upstream O2 sensor

4. do a smoke test and look for vacuum leaks (need the shop for this one)

5. do a voltmeter test on the TPS to make sure it is not the problem and keep trying to position the TPS sensor correctly (need either the shop or a to buy voltmeter)

I do have another question for those familiar with the 2001 throttle body. What is the plate on the top? There are some holes in a row inside the throttle body that go into this small area above the butterfly. I cleaned it out thoroughly and the gasket still seemed good, but that may be another thing that needs to be replaced. Does anyone even sell that gasket by itself?

Here's a picture of what I'm talking about:

https://www.tacomaworld.com/media/20161028_113642.540003/full
 
Might adjusting the tps just make things worse?

Based on what you've said you have a random misfire issue and its being troubleshot like its a throttlebody and idle issue.
 
Fix your TPS issue, or buy another one and bolt it on.

The fuel filter is an easy part to replace, injectors not so much. I'd not suspect injectors first as a clogged fuel filter prevents more debris from passing than a new filter of the same design. Fuel pressure is another issue of equal importance.

With all those 030X codes it's throwing, how does it drive, specifically how does it accelerate under load?
 
octanejunkie said:
Fix your TPS issue, or buy another one and bolt it on.

The fuel filter is an easy part to replace, injectors not so much. I'd not suspect injectors first as a clogged fuel filter prevents more debris from passing than a new filter of the same design. Fuel pressure is another issue of equal importance.

With all those 030X codes it's throwing, how does it drive, specifically how does it accelerate under load?
Click to expand...


If I can find one, I should just try a new TPS and bolt it on. I may have messed it up when taking it apart anyway.

My issue is how to properly seat and adjust the TPS once it is on because it does have those elongated screw holes that allow for adjusting the angle of the TPS sensor. Angling it too high up causes the engine to rev at about 2000 RPMs, putting it too low causes it to kill the engine. When I am able to get it in the 600-700 RPM range, it will randomly stumble as though it wants to die. In other words, it's not a strong idle when it's in the 600-700 range right now.

As for how it drives, it's not bad. The engine randomly stumbles at low speeds and in the 600-700 RPM range, but it sounds and feels fine when pressing the accelerator and going up the Los Angeles hills.

I'd rather do the fuel filter first (it has probably been about 5 or 7 years) and save fuel injectors as last resort. I have never taken off the plenum, and know it's gonna be difficult to get the gaskets torqued properly after I put everything back together. Another complication is that Amazon won't ship fuel injectors to California for some reason ($90 for a set of 6) and I don't want to go to the shop or the dealer where they are quoting $150-180 per fuel injector.

I have found many threads where my similar problem was fixed after replacing the injectors. The local shop would charge me $350 for labor and $180 per injector, so I'm trying to avoid that. If I'm replacing all of the fuel injectors, I would rather do it myself at that price.
 
Since your filter was replaced in the past......I wonder. It sucks that you need all kinds of adapters to check fuel pressure. Unless the newer changed there is a fuel pressure regulator under the top half of the plenum.


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New throttle body?

I just cannot seem to get the TPS sensor positioned correctly. I gave up and called my shop to have them take a look at it, and they told me that I shouldn't have unscrewed the TPS (duh) and that I would have to replace the entire throttle body. Their cost is $1400 for a new TB.

So, I guess I'm going to start looking for good used TBs. Any suggestions? I don't mind ordering online, but I'm also in Los Angeles if anyone knows of a good place around to either take my truck or to buy this part.

Thanks for all the advice in this thread.
 
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