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74 Fj40 DE SMOGING?

Discussion in '40- & 55-Series Tech' started by godzilla, Dec 2, 2003.

  1. godzilla

    godzilla

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    I'd like to de smog my 74 Fj40. Can the orignal computer(black box) be removed and what vaccum lines have to be retained? I'm pretty sure that the distributor has to have a vaccum supply, i.e. vaccum advance. But from which port on the carb do I hook it up from? And is there anything else I'll have to do? Thanks, Pete
     
  2. hammerhead

    hammerhead

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    I think the best idea is to do it like your 71. Hehehe. :D
     
  3. mwalls54

    mwalls54 Cruiser Nutjob SILVER Star

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    I just got threw rewiring mine and i just didn't put any of that back. i have a weber 38 carb and it only has one vaccum coming off of it so i ran it to the dist. and the ones on the intake rail i pluged all of them except the one for the brakes.
     
  4. CruisinGA

    CruisinGA

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    [quote author=godzilla link=board=1;threadid=8289;start=msg70031#msg70031 date=1070345491]
    I'd like to de smog my 74 Fj40. Can the orignal computer(black box) be removed and what vaccum lines have to be retained? I'm pretty sure that the distributor has to have a vaccum supply, i.e. vaccum advance. But from which port on the carb do I hook it up from? And is there anything else I'll have to do? Thanks, Pete
    [/quote]
    If you're 74 is anything like mine (Federal), there really isn't any desmogging to be done. That little black box-I believe you mean VSV on the DS fender apron certainly won't help power when removed, I would just leave it. It provides vacuum to the dist, some choke-related function on the carb, and channels the evaporated gas fumes from the gas tank via charcoal canister into the plenum to be burned. I don't see any reason to remove it.
     
  5. godzilla

    godzilla

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    Crusinga, thats the box I'm talking about. The hard return line ging back to the gas tank is rusted beyond repair, I just thought it would be easier to take the emmision system out of the system, my smog pump has been long removed and I'm running a header from manafre. I don't want to invest the money in a weber, its my trail rig and it will probaly eventually get a v8 conversion. And I'm sure the black box and the charcoal canister probaly needs to be replaced, I can't see spending the money to fix these items when they aren't really needed.
     
  6. CruisinGA

    CruisinGA

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    Lol, just found out this weekend that my VSV (little black box) isn't functioning correctly (no vacuum advance). My carb is also in need of replacement. Heres what I'm doing:
    Remove little black box, charcoal canister, plug evaporative emissions line from tank.
    Run the choke control servo (currently runs off VSV) on the carb directly off the carb, same for vacuum advance. This eliminates what little smog is left, while retaining all but the gas tank evaporative emissions function of the VSV.
     
  7. TheGunny

    TheGunny

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    I have a 77 FJ40, and was wondering if you had a picture of this little black box???
     
  8. laguna80

    laguna80

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    Sorry for bringing up an old thread, but I'm trying to de-smog my 72' and need some clarification. [​IMG] [​IMG]
    Now, that tube connecting the Throttle positioner and the carb body, is it ok to leave as is? Normally, they go to the VSV located on the DS front fender which is the second picture. As for the second picture, the middle line goes to the distributor, how do I close off the distributor end? It's vacuum I believe, so it should be closed somehow. Perhaps to the carb body? I need to remove this stuff, because the gas tank has no vents or connecting ports for the charcoal canister. Anyone know where I can get info to remove this stuff? I've searched a bunch of threads and the faq/tech links and haven't had any luck so far. Will keep searching in the meantime and I appreciate any help I can get.