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Hot engine won't restart

Discussion in 'Daihatsu Hi jet' started by bumpas toy, Aug 7, 2014.

  1. bumpas toy

    bumpas toy Member

    1992 Hijet Jumbo ,starts and will run all day ,but when you shut it down and try to restart it, it will not start. et it set for a half hour and it ill start right off .I adjusted the valves,cleaned the carb,checked the spark when it was hot seamed to be good .any info .would be great .Thanks .
     
  2. fupabox

    fupabox Well-Known Member

    The next time it won't start hot check for spark..coils are known to stop working when hot and work fine all day when started cold...the other possibility is vapor lock in the carb from the heat...make sure your air intake is set to the summer setting https://www.youtube.com/watch?v=BnwgjYFu6iU&index=11&list=PLD9DF80EA5FCB77D0
    the exhaust heat (in the winter setting) from the warm air intake could be overheating the carb
     
  3. bumpas toy

    bumpas toy Member

    Thanks Fupabox ,Think you are right I checked the spark when it was hot and there I spark but wary weak (orange ) when it is cold it is blue .are there another kind of coil that can be used on those systems ?
     
  4. fupabox

    fupabox Well-Known Member

    just about any coil will work...you may just have to modify the connector plug.. only the 2 positive and negative primary wires, and the secondary wire that goes to the dist. cap. At a wrecking yard an old Corolla or Tercel coil may be the same connector and just bolt on
     
  5. bumpas toy

    bumpas toy Member

    Do I use one with built in resister or without fupabox ,just getting a chance to work on it !
     
  6. fupabox

    fupabox Well-Known Member

    You shouldn't need a resistor in the coil ... As far as I know only the older ignitions with points had a resistor
     
  7. bumpas toy

    bumpas toy Member

    sorry took so long to reply ,I used a coil from a toyota ,works fine .Now I need a starter !
     
  8. Larry Nichols

    Larry Nichols New Member

    Bumpas, do you remember what coil you used, I've got a 94 that's doing the exact some thing yours was.
     
  9. Andy King

    Andy King New Member

     
  10. Jigs-n-fixtures

    Jigs-n-fixtures Well-Known Member

    On mine, the problem turned out to be a clogged charcoal canister. Which kept the gas tank pressurized, preventing the fuel return line from the fuel pump from returning fuel when the pressure went over the 2 to 2.5-psi, that the pump is supposed to regulate itself to. That caused the pressure to get height enough to push past the float valve, and dump enough fuel into the float bowl that it was running really rich, and when it had been running, it flooded in a heart beat.

    on mine the solution was an electric pump back by the tank, and a fuel pressure regulator set to 2.5 psi just before the carb. And, completely bypassing the stock fuel pump.
     
  11. Andy King

    Andy King New Member

     
  12. Jigs-n-fixtures

    Jigs-n-fixtures Well-Known Member

    Ok. Now that I have an understanding of your issue.
    You may have done serious harm. But possibly not. When you over heat an engine it can cause harm. You can warp the cylinder head. You can scratch or score the cylinder walls.. Whole lot of things which might happen. The only way to know is to trouble shoot it.

    Engines need three things to run. Fuel, Compression, and Spark. You say it has spark. So start with compression.

    You say you have compression. Have you checked it with a compression tester? Be sure you do the compression test with all the spark plugs out. Your engine should have about 145-psi in the cylinders. As you do the compression test if it lower than that, add a bit of engine oil through the spark plug holes and see if it raises the compression. Adding the oil gives you a seal on top of the piston rings. If the compression goes up after you add a bit of oil the rings are bad, and/or the cylinder walls have been gouged.

    Is the compression within 5% between the cylinders? In order for the engine to run smoothly, you need things pretty close between the cylinders. And if one is different than the others it indicates damage to the low cylinder(s).

    If the compression is low, and you have a source of compressed air, you might want to get a cylinder bleed down tester. It is a device with two pressure gauges, which you screw into the spark plug hole, and with the cylinder in a compression cycle, (both valves for that cylinder closed), you use the compressed air to pressurize the cylinder. You will always have some leek by through the gaps in the rings. And the two gauges let you determine how much, and where it is loosing air. If a valve is pad you will hear air escaping from the exhaust or the intake manifold. Head gasket is bad, the air will come out the radiator cap. Rings are bad, you can hear it through the oil fill cap.
     
    Andy King and shogun like this.
  13. Andy King

    Andy King New Member

    Well, it's been almost a year but I have finally gotten my EF-NS rebuilt and reinstalled.

    It was a blown head gasket.
    I ended up overhauling(?) the engine:
    resurfaced cylinder head, new head cylinder gasket, new bearings (connector & crankshaft), port/polish cylinder head (intake & exhaust), "valve job", carburetor cleaning (wtm), new vacuum hoses (as needed), and seals.
    The only things that I didn't do are the piston rings and cylinder walls because all three are in very good shape, surprisingly so.

    The engine is doing fabulous so far. It starts and runs every time with the slightest/quickest turn-over via the starter. This without the carburetor choke plate that I misplaced and can not find. Yes, that's right, the engine needs no choke.

    Except for a sticking valve that somehow cleared up on its own after first top speed road test (61mph).

    The throttle positioner is driving me crazy. It is not releasing when the vacuum switch cuts vacuum but operates if vacuum hose removed and reconnected every time a/c system cycles on. The valve is cutting the vacuum (i have not checked using a vacuum guage) it's as if the tp is sticking, not releasing the arm actuator. I have introduced wd-40 into the system via the vacuum hose connected to the tp.

    I could not have done it without the help of this forum. I especially want to thank Jigs-n-fixtures. Without his expertise many, including myself, would be without functioning Kei trucks.
     
    Last edited: May 7, 2023

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