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<!-- google_ad_section_start -->How to clean the potentiometer inside Throttle body<!-- google_ad_section_end -->
How to clean the potentiometer inside Throttle body
Published by Hurrican
07-01-2018
Difficulty Level: 2

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How to clean the potentiometer inside Throttle body

Hi Everybody.

I would like to share my experience about the cleaning of the potentiometer inside of the Throttle body.
I made this because I fight with bad idle after a big refurbishment and I tought I can try this as well.

I had an other Throttle body as backup so I had nothing to loose.

Before you start this please consider that this is what you need to do or not.

So do it only for your own risk!!

Throtthle body: With the help of this valve the car can control the amount of the air what is flowing into the engine. The valve chage it's degree of opening according gas pedal signal.

Potentiometer: The potentiometer is basicly a resistor what can change the resistance value according the lengt of the actual resistor path.
The inlet control valve is equipped with 2 pair of resistor.
I don't know why exacly, but I think because of the redundacy.

First Step:
Remove fixing ring arround the gearbox housing. You can do this with the help of two small screwdriver. Select one snap and hold it open with the first screwdriver and try to open the neighbor snap with the second. This can be done easily.

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Second Step:
After this done the ring can be removed so you are able to disassemble the plastic baseplate from the gearbox.
This baseplate contain the potentiometer and the electrical connection.

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Third Step:
Now you can remove the dirt cover ring and the metal cover cap above the potentiometer.
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To remove the cap I used tow small sized screwdriver. There is small holes arround the peremiter of the cover. Try to lift the ring a little and hold. Use the other screwdriver to do the same at the neighbor hole.
Attention!! Just be carefull because if you bend this ring it will never fit again perfectly.

Fourth step:
After you removed the cap you can see the potentiometer.
Mine was dirty so I removed the rotation element:
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Fifth Step:
Clean the dust with alcohol. I used 70% Isopropil alcohol and some cotton swab.
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Sixth Step:
After you done with everything put back the parts. Ensure the the rotation element can rotate easily after assably.
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Clean the motor connector with contact cleaner and put the baseplate back that is well. Do not forget the sealing ring arround the baseplate!

Final step:
After you assebled everything together check the resistance of the potentiometer.
(I found this picture in FF because I forget to shoot it. )
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Measure the resistance between (from the left) pin 1-2 and after pin 5-6.
Pin 3-4 is the 12V for the motor.
Good idea to measure it before the cleaning so you can compare the results. Theoriticaly you will measure a bit lower resistance than earyler. It is so because of the cleaning.
If you are able to move the inlet flap than you need to measure linear result.
Be carefull - do not harm or bend the inlet flap!!

In case of spikes in the result, than there is some problem with the resistor.

If you are done and the two resistance almost the same you can install the throttle body.

Do not forget to make the throttle body relearn procedure:

https://www.fiatforum.com/newbie-cen...y-relearn.html

In my case I forgot to make the procedure and after the first start I havn't had any idle and the car stalled immediately.

Unfortunately not this caused my idle problem, but anyway it's clean now.

I hope this guide is usefull for you.

Have a nice day.

Thanks Davren thanked for this post
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Old 07-01-2018   #1
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Re: How to clean the potentiometer inside Throttle body

A quick clean for the inside of the throttlebody can be done with carburetor(!) spray.
It will dissolve carbon and gunk build-up.
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Old 07-01-2018   #2
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Re: How to clean the potentiometer inside Throttle body

While IPA is OK for cleaning contacts in throttle potentiometers, these contacts need lubrication so just IPA cleaning will lead to wear and failure in the future. Unfortunatly getting the correct grease in small quantities can be difficult. A combined cleaner and lubricant like Electrolube EML200F or Servisol Super 10 is a good compromise. NEVER use silicone grease or oil on contacts as it can form a hard insulating film.

Robert G8RPI.
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Last edited by g8rpi; 07-01-2018 at 13:40.
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Old 07-01-2018   #3
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Re: How to clean the potentiometer inside Throttle body

I don't know for sure but sometimes the leading layer have self lubricate attribution.
At least I worked with plastic raw materials what contain the "libriants" for example PTFE.

Anyway, its a good point.

I not made any lubrication. Let's see what will happen.
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