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EGR Modulator

Discussion in '80-Series Tech' started by landtoy80, Aug 4, 2003.

  1. landtoy80

    landtoy80

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    I can blow in air into the bottom port of my 94 EGR modulator. The big hose to the bottom of modulator is not a vacuum but a pressure hose. On my fj60 modulator I can't blow air through the bottom port. The bottom port on the 60 has a diaphragm that opens and closes when I blow in it. Is the 80 modulator the same setup.
    Could this be my problem?
    kurt
     
  2. landtank

    landtank SILVER Star

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    There is a whole proceedure in the FSM on how to verify if the modulator is bad or not. It requires several different setups as to what hoses get blocked and whether or not the engine is running and at what rpm and how air should flow through the device. I'd suggest just following that. I had great luck diagnosing problems on my old FJ60 by just following the book.
     
  3. landtoy80

    landtoy80

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    Did the modulator test and failed the 2500 rpm and blow in Q and block R,P. THe diaphragm in the mod must of broke. It is strange that the light is not on all the time??? The light only comes on when carbon fills the modulator.
    kurt
     
  4. landtank

    landtank SILVER Star

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    From what I can see back pressure plays a role in controlling how much gas is passed by affecting that diaphram in the modulator. A few weeks back when you cleaned the temp sensor you probably made it just a little more sensitive to shut the light off for a little bit. The book has a test that is run for 3 minutes at 4,000 rpm while checking the temp sensor resistance to confirm that the proper amount of gas is passing. You might try this as well after replacing the modulator just to confirm that there isn't something more to be done to help make the repair more lasting.
     
  5. landtoy80

    landtoy80

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    I think I blew to hard into the modulator. :( Or it just broke. Now I know not to blow into the bottom port of the modulator.
    At the rate I am going with this LC, I will have a new vehicle with all the new parts I have installed.
    Maybe I should of gotten a 80 with less miles but then what would I do with all my free time? :D
    kurt
     
  6. landtoy80

    landtoy80

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    I got a new modulator. It is the same as the fj60 one that I tried :-\
    old 80 mod #25870-66010 it is green in pic
    new 80 #25870-66011 blue ib pic
    fj60 #25870-61011 red in pic

    the only dif between the fj60 mod and the new 80 mod is the manufactors name and #
    The fj60is made by ND (Nippondenso) #139000-1160
    The new 80 is by Denso #139000-3300
    I take it tht ND is now Denso, Nippond must of got kiked out :D

    I guess I should of gave the fj60 one I tried a bit longer to see if it would keep the light off ;) Or the FJ60 is just old and tired.
    kurt
     
  7. Eduardo96FZJ80

    Eduardo96FZJ80

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    Kurt,
    I also tried to use a new egr modulator that I had from my previous 89 FJ62. It looked the same with a different part #.

    I did not get rid of the MIL, until I used the "new blue " one.
    No light for over six months or so :D

    Good luck