Cleaned throttle body

hawkeye405

Silver Supporter
I cleaned the throttle body on my 4.2L 2003 TB according to the video by MAY03LT. I then removed fuse 10 and 28, waited 15 minutes and plugged the fuses back in. I started the TB and the engine idled at 1600 rpm's. I let the truck warm up and took it for a drive. The idle fluctuated between 500 and 900 rpm's and then settled down. I noticed a lag in the response when I would try to accelerate and also while trying to pass on the highway. This evening, on my way home from work it was raining so I turned on the AC. The idle jumped to 1600 rpm's every time the compressor would kick in.

What did I do wrong or miss?


Hawk
 
It is my understanding (and always works for me) when you reset the pcm, you must make sure all the a/c is off, no stereo , lights, or any load.

Turn the key on (but do not start) and let it sit for 2 full minutes. Then start the truck and let it idle for a full 10 min with no load, don't put it in gear, and make sure a/c is off.

Turn it off then start it right back up and drive normally.
 

AtlWrk

Well-Known Member
Sounds like either the PCM didn't reset properly or you have a vacuum leak.

Did you get the evap hose fully reseated to the throttle body? all hose clamps tight? The hose between the resonator and valve cover installed? Throttle body bolts tight? Seals in place? Intake temp sensor in place and connected (on the back, easy to miss)?
 

Mounce

Well-Known Member
Yeah, generally most people leave the fuses out for 30+ minutes. I don't think 15 was long enough.

Pull the fuses again and leave her for 30 minutes to an hour and then see how she acts.
 
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dmanns67

Well-Known Member
seanpooh said:
You would know for certain if your PCM had reset when your clock reads 12:00
Why would pulling two PCM fuses reset the clock? Never seen that once in the last four times I have cleaned the TB.

If you are disconnecting the battery to reset the PCM, that would cause the clock to read 1200. We do not promote disconnecting the battery. Pulling fuse #10 and #28 for 30 min accomplishes the same thing.
 

Sib

Well-Known Member
dmanns67 said:
Why would pulling two PCM fuses reset the clock? Never seen that once in the last four times I have cleaned the TB.

If you are disconnecting the battery to reset the PCM, that would cause the clock to read 1200. We do not promote disconnecting the battery. Pulling fuse #10 and #28 for 30 min accomplishes the same thing.
:iagree:

I just cleaned my throttle body a few weeks ago and pulled fuse #10 and #28 for a little over 30 minutes like dmanns67 said and it reset my PCM and clocked stayed as is.
 

Mounce

Well-Known Member
I believe if you even disconnect the battery for a few seconds it'll reset the clock.
 

HARDTRAILZ

Moderator
I always disco the battery, but then again I do not unhook the battery when welding on the truck :lipsrsealed:

I would check all the connections and that there is not junk on edge of butterfly as mentioned.
 

seanpooh

Well-Known Member
Really? I didn't know. All my years cleaning the TB, battery cable always came off. And I knew the PCM reseted when my clock went to 12:00. Just habit I suppose. I will look into the time reseting even if the cable is disconnected for a few seconds.

I know the downfall of disconnecting the battery is the actuators getting messed up but I personally never had a problem. The vehicle is 13 years old, something is always breaking regardless.
 
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hawkeye405

hawkeye405

Silver Supporter
AtlWrk said:
Sounds like either the PCM didn't reset properly or you have a vacuum leak.

Did you get the evap hose fully reseated to the throttle body? all hose clamps tight? The hose between the resonator and valve cover installed? Throttle body bolts tight? Seals in place? Intake temp sensor in place and connected (on the back, easy to miss)?
Yes, all bolts are tight and everything is back in place. Throttle body is very clean.
 
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hawkeye405

hawkeye405

Silver Supporter
BlazingTrails said:
It is my understanding (and always works for me) when you reset the pcm, you must make sure all the a/c is off, no stereo , lights, or any load.

Turn the key on (but do not start) and let it sit for 2 full minutes. Then start the truck and let it idle for a full 10 min with no load, don't put it in gear, and make sure a/c is off.

Turn it off then start it right back up and drive normally.
I'll give this a try.
 
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hawkeye405

hawkeye405

Silver Supporter
BlazingTrails said:
It is my understanding (and always works for me) when you reset the pcm, you must make sure all the a/c is off, no stereo , lights, or any load.

Turn the key on (but do not start) and let it sit for 2 full minutes. Then start the truck and let it idle for a full 10 min with no load, don't put it in gear, and make sure a/c is off.

Turn it off then start it right back up and drive normally.
It worked. Then last night I turned the AC on. At first, the idle dropped from 800 rpm to 500 rpm then up to 1600 rpms. It did this several simed then settled down at 800 with the AC cycling on and off. Thanks to all you guys for your help.
 

Mounce

Well-Known Member
Typical symptom of dirty TB is rough idle/dying when AC is on. It'll have nearly the same actions if you clean it and don't reset the PCM.

Have you pulled the fuses again for 30 minutes to an hour yet? I'd try that before condemning the TB itself.
 
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hawkeye405

hawkeye405

Silver Supporter
BlazingTrails said:
It sounds like you may actually have a problem in the tb itself. Was it doing the same thing before you cleaned it?
No, it just idled rough and had a bad hesitation upon acceleration. The TB was filthy and took a good deal of TB cleaner and rags. I checked everything once again and found a cracked dry rotted vacuum plug. I replaced it and reset the PCM by pulling the fuse 10 and 28. I waited 30 minutes, plugged the fuses back in, turned the key to the run position for 2 minutes then turned the key off and started the truck. I let it idle for 10 minutes then turned the ignition off and started it again. Off to work I went and the truck ran really smooth. On the way home, I turned the AC on while I drove. I felt the idle drop and go up several times and then it ran smooth again. Each time the AC cycles, the idle only moves about 300 rpm. Thanks again.
 

Mounce

Well-Known Member
Sounds like it's acting right now, glad you're up and running. :tiphat:
 
hello everyone, does anyone know where i can get the throttle body bolts. two of them broke off on me and i would like to replace them.
 

Mooseman

Moderator
Probably easiest would be to go to a pick-a-part and get some off a donor. If not, bring one to a fastener shop and get some regular bolts with washers. Won't be like the original but will work.
 

dmanns67

Well-Known Member
Matt_TB_05 said:
hello everyone, does anyone know where i can get the throttle body bolts. two of them broke off on me and i would like to replace them.
I had one of mine break as well. Surprisingly, I picked up a replacement bolt from a local Advance Auto. I can get you the details when I get home tonight, but I believe they are sold in packs of (2) for a couple bucks. They were on the small hardware racks that rotate. I am sure an Auto Zone would have them as well.

I just took one of the bolts with me and matched it up.
 

dmanns67

Well-Known Member
dmanns67 said:
I had one of mine break as well. Surprisingly, I picked up a replacement bolt from a local Advance Auto. I can get you the details when I get home tonight, but I believe they are sold in packs of (2) for a couple bucks. They were on the small hardware racks that rotate. I am sure an Auto Zone would have them as well.

I just took one of the bolts with me and matched it up.
Sorry for the delay, just got home from work. You will need a M6-1.0 x 45mm cap screw. Has a 10mm hex head just like OE.

IMG_20150818_000134.jpg
 

dkvasnicka

Well-Known Member
Were you able to move the butterfly when you were cleaning the TB? I did it a few days ago and the butterfly felt like it was locked in position, like 30° angle or something. I tried to push it but it wouldn't move and I was afraid of breaking it. So I took a toothbrush and worked my way around it and through the tiny slit that was left there.
Is this some new design/feature of later I6s (2006)? I saw people on video moving it as if it was just lightly spring-loaded.

As for the engine, I had the #10 and #28 fuses out for an hour and I think it did the trick. The truck had a bit rough idle when I started it the second time (first time was ok, it even took me turning on A/C with no stalling) and when I tried to step on the gas a bit and rev it it felt like it would suffocate... but I let it run a minute or so more and then it revved well. Drove it today, no lights, maybe a bit more peppy. The TB wasn't that bad before, I guess.
 

coolasice

Well-Known Member
Were you able to move the butterfly when you were cleaning the TB? I did it a few days ago and the butterfly felt like it was locked in position, like 30° angle or something. I tried to push it but it wouldn't move and I was afraid of breaking it. So I took a toothbrush and worked my way around it and through the tiny slit that was left there.
Is this some new design/feature of later I6s (2006)? I saw people on video moving it as if it was just lightly spring-loaded.

As for the engine, I had the #10 and #28 fuses out for an hour and I think it did the trick. The truck had a bit rough idle when I started it the second time (first time was ok, it even took me turning on A/C with no stalling) and when I tried to step on the gas a bit and rev it it felt like it would suffocate... but I let it run a minute or so more and then it revved well. Drove it today, no lights, maybe a bit more peppy. The TB wasn't that bad before, I guess.
Did you unplug the tb before trying to move it? Always unplug it prior to cleaning. When plugged in the stepper motors are holding it's position and you could risk damage to it if you try to move it.
 

dkvasnicka

Well-Known Member
Did you unplug the tb before trying to move it? Always unplug it prior to cleaning. When plugged in the stepper motors are holding it's position and you could risk damage to it if you try to move it.
Yep, I was holding the TB in my hand, it was out of the car. That's why it seems so weird to me. The car drives normally so it definitely isn't stuck or something...
 

coolasice

Well-Known Member
They are pretty tough to get moving but will move, we're you pushing the right way?
 

Mooseman

Moderator
If you move it one way and it seems to just stop closed, you're going the wrong way. It should open the other way. You can feel the resistance and the motor inside while opening by hand. It can take a bit of force to move it but it shouldn't bind.
 

kickass audio

Well-Known Member
The throttle body moves both ways but you will notice that one direction will go a little ways and then shut itself totally flat which I think is what happens when you shut off the engine to cut off the air supply. The other way is where it opens up the butterfly on it and let more air through. I myself clean the throttle body and open and close the throttle plate to make sure it has no binding. I of course do it off the truck.

What you will notice is in the resting position, the throttle body is leaning a little bit. If you have it bolted on the intake manifold, you will be pushing the upper most part of the throttle plate to get the throttle plate to open up more. If you push on the lower part of the throttle plate that is closest to the valve body, it will cause the throttle body to close itself flat shut.

I'm a rebel and clean my TB with carb cleaner because I more often than not am cleaning carbs on my small engines than I am throttle bodies and have had 0 problems in doing so. I spray the cleaner on a rag and wipe it clean. I don't spray anything inside/on the throttle body.
 

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