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vacuum manifold?

Discussion in 'Trade-A-Part' started by AaronRS4, Oct 31, 2013.

  1. AaronRS4

    AaronRS4 Member

    I just bought my first mini truck and have noticed that I seem to be missing part of my vacuum system. Its a 92 Daihatsu Hijet S83p. According to the vacuum schematics I've found, there appears to be what I can only describe as a vacuum manifold that is supposed to run along the front side of the carb. Mine appears fo be missing, and things have been re routed and plugged etc.... just wondering if any one out there would happen to have a spare one of these manifolds I could purchase. If not, I'll just pick up some vacuum hose tees and do my best to replicate the schematic. The truck runs in its current state but will stall out when approaching a stop sign with the clutch depressed an your foot off the gas. Always starts right back up but you have to feather the throttle to keep it going.
     
  2. muddy moose

    muddy moose Member

    Not sure on that rig........I have a carry, have you tried to adjust the idle up so it doesn't die and made sure you don't have any vacuum leaks?
     
  3. AaronRS4

    AaronRS4 Member

    I have gone through all of the vacuum lines and replaced them all. I figured that was easier than chasing vacuum leaks down the road... I just used vacuum line and "T" fittings to replicate the manifold for now, using a drawing I found on minitruckcentral.com. Nothing on the drawing is labeled by anything other than a number, and quite frankly, I have grown up in the fuel injection age and my experience with carburetors is limited to small engines. What/where is the idle up adjustment? I assume this is different than the cold and warm idle adjustments?
     
  4. muddy moose

    muddy moose Member

    Have you looked at the "despretly needing carb help" post or looked up any of the posts on carbs for ur rig? My idle screw is on the side of the carb that is closest to the front of the truck. My choke is the bumper side. Lots of adjustments on the choke side and only the idle adjustment on the other. Just don't go and start turning screws!!!! Hahaha not till you know what they are. Lots of info in the group. I would have never figured mine out without it!! Good luck
     
  5. Jim Nelson

    Jim Nelson Active Member

    If it's like the S80,and I think it is, the idle adjustment screw is on the right side of the carb as you are looking at it from the air filter side.On the air/fuel mixture screw,which is on top of the carb your initial setting is snug it down then back out 4 1/2 turns.It seems a lot but it works on mine.
     
  6. AaronRS4

    AaronRS4 Member

    Muddy- I have read that thread, but it seems to mainly pertain to diagnosing which carb he was using and with which setup his truck was... I know everybody says they are all "similar", but, to someone like myself they are completely different. If I get the time this weekend I'll actually post for help in the correct section as opposed to the parts section. I have a friend coming over tonight to bring me a timing light, and we'll see if that has anything to do with my issues...
    Jim- is that air/fuel adjustment the one on the top in the middle of the triangular do-hicky? See.... if I had a drawing with something other than a number next to the parts, that would help to clear up a lot of confusion... Then I could at least ask questions and respond without looking quite as clueless.:p
     
  7. muddy moose

    muddy moose Member

    Hahaha its all good. If ya include the number people like Jim and others, not me Hahaha, would know exactly what hose your talking about. I'm in the same boat as you. I don't know much either. I just happen to get lucky at times and others people are kind enough to let me mess it up real good, then bail me out hahaha. What better way to learn right? Hahaha does the end of your tail pipe have black soot in it? Or is it clean
     
  8. AaronRS4

    AaronRS4 Member

    Its a bit black, but not what I would call bad... its dry, not wet, I know that much...
     
  9. Jim Nelson

    Jim Nelson Active Member

    If you are referring to the white plastic dohickey yes that's it.On most carbs you tighten it and back off 1 1/2 or 1 3/4 turns,this is the only one I've seen that you open it up that much.If you have everything else in good shape you can get it running with this setting then hook up a vacuum gauge and adjust it til you find the highest reading and that should be right.
    It's a good idea to check your timing like you're doing as that effects everything.The book says 7 deg. advanced but depending on your altitude you'll probably want at least 9.
     
  10. AaronRS4

    AaronRS4 Member

    The only white plastic thing I have on the top of my carb can best be described as a "thumb screw" near where the carb bolts to the manifoldand only has about 1/3 of a turn to it.... there is a "stop" built into it that prevents you from turning it any further than that...
     
  11. Jim Nelson

    Jim Nelson Active Member

    That's the air fuel screw, it must still be original as the ones I've seen,not that many, are fully adjustable.That plastic cap pops right off with a screw driver and reveals a plain old brass needle screw and the manual says that the initial setting is 4 1/2 turns.I have 3 of these carbs and 2 of them still have the plastic cap on them but are free turning so I guess yours is like the weed eaters and such that don't want you to adjust them.
     
  12. Jim Nelson

    Jim Nelson Active Member

    Go to the Daihatsu section and search for a post titled" choke help....please" .In this is a reply from fupabox that gives a good adjustment tutorial.He also has a video somewhere in there on the carb that's really good. Fupa is pretty much the go to guy on the S83.
     
  13. spaner

    spaner Well-Known Member

    Hey Jim,
    It's been my experience, that with the weed-whacker 2-cycle, the main mix is set at the factory so that you don't burn the piston on the 2-cycle mixture touchy bastards. I still end up burning them, any little piece of grit in the main jet from a dirty bowl, and by the time you notice it...she rattles,
    Anyway, I say, that guys are always looking for the simple solution, and this leads them to this screw. The cap is there from the factory for a reason as well. It is for the co2/no fine adjustment during E-testing, 1/3 is all that is allowed and is in the ballpark(manuals use the same reference). I too have done much testing with the screw setting and have found no advantage to running in any other position other than the factory one.
    "Their looking in the wrong place"
    Anything, from a vacuum line leak, to an incorrect routing of the lines, to a cracked main seal on the carb plunger, to a bad gas cap seal.
    Look everywhere else BUT that screw, including the rest of the carb.

    For testing, pull the main manifold vacuum line off while running. If the engine smooths out, and the rich smell dissapates, you got problems, and a co2/no screw ain't gonn'a do not'n for you...

    ;)
     
  14. Jim Nelson

    Jim Nelson Active Member

    I was probably wrong as I thought this was the same carb as the S80/81 because Leon at Daihatsu help told me it was but after looking further I found that thread with Fupa's comments and realized it is probably different.
     

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