MAF sensor Crystal Clean (well, sorta) Throttle Body plate, not so much

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cyberpriusII, Sep 27, 2015.

  1. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    This was my last weekend before "winter" to do Prius stuff...

    One thing I did was pull the MAF and clean the throttle body.

    The MAF was pretty much clean. I did spray it down, but not much in the way of deposits.

    The Throttle Body, while not "filthy" did have some deposits, well, more than some.

    I cleaned it best I could, but was a little nervous about it and was afraid to use too much CRC Throttle Body Cleaner as I have read that it could do damage if you shot too much down into the hose.

    Anyway, is it normal to have a clean MAF, but a somewhat mucky Throttle Body?

    I would think both would be "yucky." Or am I over thinking this? As usual....
     
    #1 cyberpriusII, Sep 27, 2015
  2. AzWxGuy

    AzWxGuy Weather Guy

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    I don't think I ever saw any deposits on the MAF. But the hot wires you are cleaning are up in there and a little hard to see. The throttle plate cleaning should be carefully done. What you want to avoid, and Patrick Wong will agree with this, is spraying too much solvent in and around the throttle plate shaft where it exits the throttle bore. It is possible to dissolve deposits and then force them further in to the throttle shaft bearing area and perhaps further into the throttle position sensor area. Not good. What I usually did was a little spritz of solvent near the shaft bearing, move the throttle shaft back and forth, then apply absorbent towel to the extract the deposits. A couple times per side and you should be good. Another area to pay particular attention is where the throttle plate approaches but doesn't quite touch the throttle bore. Immediately on the other side of the plate is where a lot of carbon will build up. I use Q-tips soaked in solvent to clean this area back to shiny aluminum.
     
    #2 AzWxGuy, Sep 27, 2015
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Nutzaboutbolts recommends to just spray carb cleaner on a cloth and then wipe the throttle body throat and plate, never spray directly.

    Also, I believe there's a special fluid for the MAF sensor? I think in a pinch something like vodka might do, tho not sure. The concern is carb cleaner may leave oil residue?

    What's done is done, likely all good anyway.
     
    #3 Mendel Leisk, Sep 27, 2015
  4. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    Thanks to you both....

    Mendel, if I would have had vodka out there, that would not have been a good outcome! :eek:

    I used CRC MAF sensor cleaner on the MAF and CRC throttle body cleaner on the TB.

    I probably could have gotten the TB a little cleaner, but most all of the gunk was on the edge of the plate where it seats against the "tube." did the best I felt comfortable with.

    Hmm. Vodka. Don't have any at home, probably good that I don't. At the moment I am making do with Pinedrops IPA from Bend Oregon, Deschutes Brewery, which does a good job of reminding me of home -- Oregon. I do have to be at work at 6 a.m. Monday.
     
    #4 cyberpriusII, Sep 27, 2015
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  5. AzWxGuy

    AzWxGuy Weather Guy

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    Your article persuaded me to take a look at my intake air area just now. The Gen III is a bit different. Easier to get at the MAF but much more difficult to do the throttle body. It is amazing how much carbon builds up just inside that little gap between the throttle plate and the throttle body. And the gunk is tenacious too, requiring about half a pint of elbow grease to carefully remove. What I have noticed after cleaning this area on both the Gen II and the Gen III is a smoother transition between ICE/electric (decelerating) and all electric. The ICE start might be a little smoother on acceleration too, but it's harder to tell with the electrics at full power. The ICE doesn't seem to stumble as much when transitioning off and on. Maybe an improvement in mpg too, haven't noticed.
     
    #5 AzWxGuy, Sep 27, 2015
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