ICE throttle plate cleaning

it appears that the cycle only occurs after the engine is done charging the battery, instead of shutting off the engine keeps cycling high-low; however, no arrows are present on the screen. This is with the car stopped and in park.

 

1. I understand that you had removed the MAF sensor. Check the tightness of the two screws securing the sensor to the air cleaner housing assembly. Also check the integrity of the rubber O-ring that seals the junction between the sensor and the housing assembly.

2. Check the tightness of the metal clamp that secures the bottom of the air cleaner housing assembly to the throttle body.

3. Check the two PCV hoses that connect to the throttle body. One of those hoses does not even have a clamp holding it on. Make sure that both hoses are attached to their respective fittings securely.

4. Check the engine oil dipstick and the engine oil cap to make sure that both are tight.

5. Check that the wiring harness connectors to the MAF sensor and the throttle body are fully inserted and secure.

The point of #1 - #4 above is that there must be no air leaks in the engine air intake system after the MAF sensor, which monitors the flow of air into the engine. If unmetered air can bypass the MAF sensor, this will cause a lean mixture and a rough idle.

The point of #5 above is to make sure that the engine ECU has good electrical connections to the MAF sensor and the throttle body. If the connections are intermittent that can cause engine driveability issues.

Good luck.

 

Tool should not be needed really unless its really bad.
I rip up a tee shirt into a long strip and stuff it down the throttle body all the way into the bottom of the bore with a long tail hanging out. Soak that strip with Carb Cleaner.

Wearing rubber gloves preferably Diamond Grip's from Auto Zone soak that T shirt strip in carb cleaner and using your fingers and the soaked strip scrub the bore and butterfly. Soak the hell out of it and the T shirt strip will hold it all. It will clean that oil out out the bottom of the intake too. When you pull that T shirt out of the bore it should be sparkling clean.
Avoid the MAF if at all possible. It does not really get that dirty and is easily damaged if you do not know what your doing.

After its all dry use some spray lube on the tb butterfly spring too.

Plus look at the front of this thread and you'll see where I bypass the TB coolant loop also. That takes all the coolant heat off the TB bore and more importantly does not cook the expensive TB motor. I live in Fla and its not neceesary to keep the TB and intake at 190 F all day. The intake is quite cool when bypassed evidenced by my ScanGgauge readings. I run bypassed all year long.

Its a very old tuner trick.

But If your in a cold climate it is very much needed in the winter though or you may see vapor lock.

Car runs really good.

 

okay, I thought the above fixed it but after taking it for a quick drive, when i came back it is still doing it .

When i removed "the MAF" sensor, well i thought I did, I basically removed the air filter, then removed the two bolts the connect the black plastic and held it back while cleaning. So i guess I really did not remove the MAF.

I did check #1, to the best of my ability only regarding the tightness. I don't think those screws moved.

#2 - I tightened a decent amount, was hoping that was the problem.

3# If I am looking at the same pvc valves, both in the front, one on each side, both are attached. Both have clamps though. Also, I poured some soapy water on them and no bubbles appeared.

#4/5- checked, no problems

One comment about my MAF, it looks like it was dipped in ashes. It does not look orangish or like any of the pictures on here. Could that be the problem, maybe the cleaning somehow made it act up, realizing how dirty it is?


I let my girfriends dad listen to it, and he said it sounds as though something electronically is trying to turn off/on.
It is odd, when charging the traction battery the engine sounds normal; however, once its done the engine will not shut off, it keeps doing the describe.

Any other ideas? Im guessing its okay to drive it back, I mean I sort of have too lol.

Thanks, Patrick, and anyone else for any suggestions/advice

 

I am wondering whether you got throttle body cleaner on the MAF sensor, which has contaminated it?

If your local discount auto parts store is open today, then I suggest that you buy a can of MAF sensor cleaner (which is not the same as throttle body cleaner). Remove the MAF sensor so that you can clean it properly. Take a look at the O-ring on the sensor, while you are at it. (If you can't get hold of MAF sensor cleaner, then you can try using rubbing alcohol as a cleaner.)

Hopefully that will help.

 

I was able to make it back to school with no problems, it seems as though the problem is only noticeable when its stopped/idling.

I was almost wondering the same about getting it contaminated. I was pretty careful but i guess the fumes/spray could have came up when i sprayed. It was pretty dirty in there and I did have to use a good bit of that stuff.

I will give the MAF sensor a cleaning wend when I go to my uncles, since I don't have any tools up here.

Hopefully thats all it needs.

Thanks, again for everything.

Herb Partsch

 

Cleaning the MAF sensor did the trick, runs like a charm.

It actually seems like its getting better gas mileage, but too early to tell.

Thanks!!!

 

Good to hear

 

it is interesting, today it seemed to act up again, not the reeving. I cleaned it once again. Also using alcohol. Took it for a drive and it seems good, but ill continue to see.

 

The air filter is in good shape and installed correctly, right?

 

Yep, I think it just needed a extra cleaning. It's working perfectly now.

Thanks, everyone!

 

just an update, my mpg has increased from 44/45 to 48, and its been considerably cooler.

Thanks everyone,
A big thanks to Patrick!

Herb Partsch

 

FYI engine reving will also be caused by the TPS setting being too high.

 

Folks:

I'm going to be cleaning my throttle plate for my Gen II Prius later this weekend. I decided to tinker a bit with it tonight to see if I could rotate the spring to see if the throttle was stuck. Is there a button behind the spring that I need to push? Or do I just try to do something to the spring? Any help would be appreciated!

 

All that is needed is to have the car IG-OFF. Then you can easily rotate the spring-loaded throttle plate shaft.

Pls do not contaminate the mass air flow sensor with throttle body cleaner.

 

Yes take what Patrick said seriously, if contaminated its a real pain in the butt. I was even really careful.

 

Remove the MAF sensor before spraying TB cleaner down the bore. Most TB cleaners also have some lube in them, and that will end up on the MAF hot wires.

The MAF is very easy to remove, and one can spray the appropriate MAF cleaner inside the MAF barrel to clean the hot wires.

With my FJ, it appears to benefit from regular MAF cleaning every 2-3 months. Primarily due to very short trip use - last year I put on a whopping 4,100 km ! - and very cold winter temps down to -40

With the FJ, the TB is very easy to remove. Unbolted, there is just enough slack in the TB coolant hoses to allow me to swing the TB about 2 inches away from the intake.

I lay the TB on a rag and liberally spray TB cleaner on both sides of the blade, especially the backside that has the buildup.

For some vehicles cleaning the MAF and TB really can help restore performance, solve driveability issues, and restore fuel economy. My Prius didn't seem to be bothered too much by a dirty TB and MAF, though every 3-4 years is a good idea

The FJ is different. The MAF every 2-3 months, the TB at least every fall, preferably every fall and spring

 

Thanks for the advice folks. I am planning on taking out the MAF before spraying TB cleaner. I might even try and remove the air hose to better clean the backside of the TB plate, as there might be some buildup.

So if I understand Patrick correctly, I can leave the car off while performing the cleaning, correct?

 

Not only "can" you leave the car off, you "must" do so for safety reasons.

Also note that a recent Toyota TSB on Classic throttle body cleaning suggested that you remove the air cleaner housing, spray the throttle body cleaner on a clean cloth (or paper towel), and use the cloth to scrub the throttle body interior and throttle plate. The practice of spraying cleaner into the throttle body is discouraged as this may carry dirt along the throttle body shaft into the throttle motor.

 

Thanks for the info-I figured I needed to leave it off, but wanted to double check. I've done the basic DIY work (engine and cabin air filters, Oil change, etc), and want to make sure that I do this one right.