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Hijet is running worse in a number of ways. Any suggestions appreciated.

Discussion in 'Daihatsu Hi jet' started by Clauss, Nov 29, 2022.

  1. Clauss

    Clauss New Member

    Hi. I drive a 95 Hijet s110p 5speed manual. It has run great since I got it, but I recently started having several issues that I am hoping are all related and I'm looking for help with. Any suggestions welcome and appreciated.
    I keep track of fuel economy and several weeks ago noticed a drop from where it has been for the past year (around 32 mpg). The last six or seven fill ups it has lost about 1 mpg at each fill up. I'm now around 25mpg. At the same time that started the engine began cutting out when I would come to a stop at stop signs. At first it was only in the first couple minutes after being on the road, but now it happens a lot at many of the stops along my drive to and from work. It stops running before I even come to a stop sometimes too as I am slowing down.
    I have noticed it has significantly less pull going up hills and accelerating on the flat. Hills that I used to go up fairly easily in 4th gear now slow me way down and I have to shift into 3rd. One last thing is that it idles rougher than normal and I have to tap the gas fairly frequently to keep it from stalling out. When I first start it after it has been sitting for a day the engine doesn't rev right away it takes a couple of taps on the gas. I think/hope all of this is related. What are your thoughts? Has anyone had similar issues?
     
  2. shogun

    shogun Active Member

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  3. Jigs-n-fixtures

    Jigs-n-fixtures Well-Known Member

    When mine did teh same thing, it turned out to be a clogged charcoal canister. It causes the fuel tank, to pressurize and that keeps the fuel return line from the fuel pump gets pressurized. This bumps up the fuel pump discharge pressure. which in turn pushes past the needle and seat, casing the truck to flood.

    Check your plugs, I’m guessing that they are a deep sooty black.

    My solution was to bypass the fuel pump, by installing a filter and electric fuel pump back at the tank, and installing a pressure regulator immediately before the carb. You need to block the return line from the stock pump to the tank, back at the tank.
     
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  4. Clauss

    Clauss New Member

    Thank you for these suggestions. Do you know if the vacuum line diagram code the s83p is similar to my s110p? I've seen some vacuum hose sets available on Yokohama and some parts sites. Are the super specific for each vehicle or will vacuum lines from most part stores around here do the trick?
     
  5. shogun

    shogun Active Member

  6. Clauss

    Clauss New Member

    Sounds likely that this is the same issue. I'm not super skilled or experienced when it comes this kind of work, but your bypass seems fairly straightforward and I have a friend that could most likely help me through it. I'll be sure to check the plugs before I do anything else. One question I have is if it is possible to clean the carbon filter or replace it with a similar model/size filter from another vehicle? I saw a video where someone used an air compressor to force air through the filter to force out any clogs. Is this an option to save me a risky (for my experience level) bypass? Also can you confirm that the attached picture is the carbon filter in question? Thanks again.
     

    Attached Files:

  7. shogun

    shogun Active Member

    Clauss likes this.
  8. Myersdrew88

    Myersdrew88 New Member

    I have a s110p that I want to bypass the manual pump with an inline electric. Do you happen to have pics of what you did or know what I need to do with my return lines?
     
  9. Tripthyme

    Tripthyme Member Supporting Member

    Get a regulator with a return. Your pump will last longer not pushing against a wall
     
  10. ERINSON DURAN

    ERINSON DURAN Member

     
  11. ERINSON DURAN

    ERINSON DURAN Member

    Hello i have a 1999 hijet truck that when is cold it Revs. High like 4000 rpm's and when it warms up it will not respond to any adjustment and just stalls. it runs and drives fine down the road but when coming to a stop will stall. i've had the carb replaced 2x (from ebay) . all vacuum lines and valves have been removed by the previous owner and I don't know what to do since I bought the truck without them. The distributor have two vacuum lines but I don't know if I can bypass them. The distributor have two vacuum lines and when I connect the bottom line to the Manifold I can see a change. Can I bypass them? How? I included some pics for reference. Please help me with this because it is driving me crazy. Thanks Erinson
     
  12. Tripthyme

    Tripthyme Member Supporting Member

    The lines from the dizzy are advance/retard. Have you checked your ignition timing? Adjust the carb to 950rpm when cold once warm adjust to 950 again. Pull plugs check for black/brown to know if you are rich or lean, readjust accordingly, then set your ignition timing. Hope this gets you going
     
  13. ERINSON DURAN

    ERINSON DURAN Member

    Where do those lines gets connected to? Since they were not connected to anything. Thanks
     

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  14. Tripthyme

    Tripthyme Member Supporting Member

    One goes to the carburetor vacuum the other to a tee but ultimately connects to manifold vacuum. I'm currently driving to work when I get there I will send you some diagrams in 20 min
     
  15. ERINSON DURAN

    ERINSON DURAN Member

    I'll get some vacuum hoses now. So Basically one goes to carburetor and the other one to the Manifold?
     
  16. Tripthyme

    Tripthyme Member Supporting Member

    Yeah. Whats you model # and engine? I can send you some diagrams now. 4mm vacuum hose is what you need and a vacuum buddy, I got mine from napa for 50$
     
    Last edited: Dec 16, 2022
  17. ERINSON DURAN

    ERINSON DURAN Member

    Ok so you are saying that I can get an aftermarket vacuum boddy. Remember I got the truck without any vacuum hoses and valves. My truck is a Kia Towner which is the same as a Daihatsu HIJET (all the parts and diagrams are the same) do you have a link or a picture of it? Thanks
     
  18. Tripthyme

    Tripthyme Member Supporting Member

    Vacuum buddy is a manual pump to check Vacuum lines, check valves, bleed breaks or anything that needs suction. Its a tool. I sent you a link to my vacuum files.
     
  19. ERINSON DURAN

    ERINSON DURAN Member

    Ok, I'll have a big problem with this because there are no vacuum lines and valves in this truck. I'll check the diagram now. The bottom line is connected to the Manifold and the upper I'll connect it to the carb. Ill let you know Thanks
     

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  20. Tripthyme

    Tripthyme Member Supporting Member

    Most lines can be deleted from what I have seen others do but I have not got mine 100% figured out yet. I believe i know where mine messed up but haven't had time to take care of it yet to know for sure.
     
  21. shogun

    shogun Active Member

    @ERINSON DURAN: please add you model, built year and engine as signature, then it is not necessary for us to always ask for such detail. Go on top right to you name, click on the name, as new window will open and then go to signature, see my sig as example
     
  22. ERINSON DURAN

    ERINSON DURAN Member

    Finally got it on, idling at 1100. Cleaned the carburetor and connected the 2 distributor hoses to the Manifold and the carburetor. Now it is a little hard to start when is hot. What could it be?
     

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  23. Jigs-n-fixtures

    Jigs-n-fixtures Well-Known Member

    Timing is first guess. And the air fuel ratio is probably wrong once it gets warmed up.

    Get the timing right, and then set best lean idle. It looks like your replacement carb has a manual choke. Which makes things a bit easier. Stock idle on my S110 is 1200-rpm, and I set the cold idle to 2500.

    Search for “Best Lean Idle”. I did a thread a while back on how to do it.
     
  24. Tripthyme

    Tripthyme Member Supporting Member

    Let me search that for you because I also need to know!

    https://minitrucktalk.com/posts/104975/
     
  25. Jigs-n-fixtures

    Jigs-n-fixtures Well-Known Member

  26. Tripthyme

    Tripthyme Member Supporting Member

    Nice! Lots of good info! I bug grimports at least 1 time every 2 weeks with my problems and I think you need to go work for them. Your info is always just as in depth as them and easy to understand.
     
  27. ERINSON DURAN

    ERINSON DURAN Member

    Finally got my truck up and running the way I wanted. I created a video of how I swapped the original carburetor to a motorcycle one. Here is the link
     

    Attached Files:

    Tripthyme likes this.
  28. Tripthyme

    Tripthyme Member Supporting Member

    Make sure those lines are fuel rated or you will be replacing the jets on the carb soon. Napa numbers for that filter are 3040 and 3041. And I believe that valve on the oem carb is egr related... mine went to the charcoal canister while fuel return came off my mechanical pump
     
  29. ERINSON DURAN

    ERINSON DURAN Member

    Fuel line are gas rated and so far I'm happy with the swap. Only have been a week!!!
     

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