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My new 1990 HDJ81

Discussion in '80-Series Tech' started by TuffMudder, Apr 18, 2018.

  1. TuffMudder

    TuffMudder Still working on my FJ55!

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  2. TuffMudder

    TuffMudder Still working on my FJ55!

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    Well the new airbox and snorkel did not turn out as I'd hoped. Got it back today, drove out of the s

    hop noticing a huge white smoke trail behind the truck that had not been their before and within 100ft of leaving the shop, the car died. It did again on the short trip back.

    It appears then engine isnt getting enough air and is getting too much diesel for the air supply (Musical interlude *I can't live! if livin' is without you* ).

    I had the box made around an ac delco a3181c. It has a 3 inch inlet to match the 3 inch snorkel, and the outlet is matched to the turbo intake at 2 1/2".

    If it take the filter out it doesnt improve the white smoke, but the engine seems to run fine but will still choke out if i run boost at 10psi for more than about 20-30 seconds. I'm going to pull apart the fender hopefully tomorrow and run it without the snorkel or filter and see if it's back to normal.

    Anyone have any other suggestions? Am I stuck with going to a bigger box different filter and 4" snorkel? If i have the snorkel and airbox intake at the right size, do i still need an outlet larger than the turbo intake?

    Any suggestions are welcome
     
  3. mudgudgeon

    mudgudgeon

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    Did anything else get touched? White smoke is unburnt fuel.
    Poorly burnt fuel usually does as black smoke
     
  4. mudgudgeon

    mudgudgeon

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    Sorry, half a post there.

    Sounds odd. Even if the airbox is too small, not sure how that causes white smoke.

    White smoke is raw, unburnt fuel, you'll probably smell the fuel. You'll see white smoke if timing is way off, or air is getting in the fuel system (which screws up timing)

    Black smoke occurs air/fuel ratio is too rich, and combustion is incomplete (but fuel is burnt). I think if it was a bit choked for air, you'd see black smoke, not white.

    Was smoke definitely white? Not blue, oil smoke?
    What was done with the PCV hose? I'm wondering if its plumbed in in a location that is pulling a vacuum (and oil) from the PCV/rocker cover. If so, you might see whiteish oil smoke. If this is the case, there's a real risk of the engine running away burning it's own oil. Trust me , you don't want to hear your 1hd-t revving uncontrolled. Stopping them when the taco needle is off the clock is not easy!

    What's the dimensions of the panel filter? My impression is that most have a much smaller surface air than a stock filter. I don't see it causing white smoke, but a restriction might help create a vacuum through a poorly located PCV hose.
     
  5. Crab Sack

    Crab Sack

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    I would agree that the new air box Pcv hose location may be the issue now pulling a vacuum on the pcv line sucking in oil. Either not a large enough filter media surface area or Venturi effect. Try emptying out the oil catch can And then running pcv to atmosphere. Then see if the smoke clears.
     
  6. TuffMudder

    TuffMudder Still working on my FJ55!

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    Complete list of work done:
    Replaced the airbox
    Added a snorkel
    Mounted fmic and drilled pipimg holes

    Dimensions are 12.6x10x2.6

    I'll post up a Pic of the pcv location

    I reread the airbox thread and had latched onto the big boys Comme to and hadn't registered torfabs commits. According to them, amd as @mudgeon had mentioned, anything less than 4" in and out at the air box creates a vacuum. I hadn't thought about the pcv hose them sucking in oil. It connects to the air box upper (outlet) half so it would have free access to the intake
     
  7. cc93cruiser

    cc93cruiser CRUZAHEAD

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    Are the factory skids on JDM 80s any good? Will they bolt right on to our NA 80s?
     
    Last edited: May 16, 2018 at 10:17 AM
  8. IanB

    IanB

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    They are made of fiber reinforced plastic of some sort, not overly beefy compared to aftermarket stuff.
     
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  9. IanB

    IanB

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    How about some pics of the engine bay? @mudgudgeon is on the money as to what kind of smoke comes from what conditions.
     
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  10. cc93cruiser

    cc93cruiser CRUZAHEAD

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    O snaps, scratch that idea... Was thinking they were full blown steel skids.... might be a good idea to get a hold of these and make steel ones using the same pattern as these oem plastic ones.. Thanks for the input..
     
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  11. TuffMudder

    TuffMudder Still working on my FJ55!

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    What he said

    I snapped a quick pic of the pcv before heading to work. I can get more after work if needed. The pcv enters the air box on the turbo side of the filter

    [​IMG]

    So just putting all of this together, it looks like the airbox pcv inlet location, or possibly the air inlet and outlet are creating a vacuum that's pulling from the pcv, so i'm getting not enough air and pulling oil into the intake. Smoke looks white, but what do i know. Is there a way that this process could have also caused diesel to be pulled into the turbo? otherwise it looks like i'm dealing with oil smoke and i just can't tell colors very well.

    Assuming i'm hearing you guys correctly, would changing the pcv location on the airbox be enough, or am i looking at needing to go full 4" intake right up until it boots down to 2.5 at the turbo?
     
  12. IanB

    IanB

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    If I'm understanding where the PCV routes correctly, if you're pulling oil in the PCV hose, you'll have oil pooled in the bottom of the filter housing? Easy to check if that's your issue if that's the case.
     
  13. TuffMudder

    TuffMudder Still working on my FJ55!

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    Yeah, i thought about that an no, there is not oil in the air box or on the filter. I'll get a better pick of the pcv in relation to the 2.5" outlet (it was ordered at 3" but there was a miscommunication with the welder) to the turbo at lunch when i go back to the shop its in
     
  14. TuffMudder

    TuffMudder Still working on my FJ55!

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    Come get ya Some wanted to take another look at the intake this morning so i dropped it off. I picked it up at noon and all problems seem to be resolved in terms of smoke and engine not getting enough air. In addition, acceleration is noticeably improved. They did 2 things:

    Switched out the ac delco for a higher flowing k&n filter and they swapped the pcv tubes at the catch can (not sure what this would effect unless there's a one way valve in the can). I assume it was just going to the new filter that made the difference. Here are better pics of the system including a pic of how close the pcv inlet to the air box is to the air box outlet to the turbo.

    PCV inlet to airbox
    [​IMG]

    [​IMG]
     
  15. IanB

    IanB

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    If a clean AC Delco filter was too much restriction for the truck to run correctly, I don't think this is the end of your issues...just saying.
     
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  16. TuffMudder

    TuffMudder Still working on my FJ55!

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    The difference was pretty dramatic. Is there any chance that swapping the pcv hoses had any effect? I assume not, but i have to ask.

    If the pcv swap was of no consequence, any thoughts on what i should do next? @IanB? Everything seems back to normal now, but i get your point
     
    Last edited: May 16, 2018 at 3:01 PM
  17. IanB

    IanB

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    I'm happy to hear it's running the way it should again, but an air filter swap itself is unlikely to have made the difference.

    You can easily swap the PCV hoses back and see if the issue comes back, I'd start there.

    I've heard of the silicon hoses/bends collapsing under vacuum, it's always possible that's happening under load.
     
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  18. dan1554

    dan1554

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    Looking back, clear fuel lines would be one of the first mods I would make to my cruiser, if you don't have them already. I doubt your problem is related to air, or the catch can for that matter. Even if it doesn't solve the problem, at least you'll be able to rule out fueling.
     
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  19. mudgudgeon

    mudgudgeon

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    Good point about silicon hoses collapsing.
    The factory intake piping has a long steel sleeve in between the rubber bends to help prevent this.
    I replicated this when I did my turbo install as hoses collapsing is a known issue with after market install.

    I agree that swapping the filter alone is probably not the solution, easy to chuck the AC Delco one back in and see what happens.
    I've had brand new aftermarket filters trigger the blocked filter light in my HZJ105, so maybe filter along with the small inlet, outlet is part of the problem.

    K&N filters is definitely not a permanent solution if you take this anywhere outside the city limits. They don't have a good reputation for effective filtration of dust.

    I think it would be a good idea to make everything at lest equivalent to the OEM air box. Inlet/outlet size, hose sizes etc.
    You can be sure that at least some testing and development went into the design of the OEM intake. Inlet and outlet size and shape and location can have a big impact on air flow.

    The OEM PCV hose connects in after the air filter. Diesel engines don't usually pull a vacuum through the intake, but if the air box is choking it, it's possible.

    Do you have a pic of thre catch can?
     
  20. TuffMudder

    TuffMudder Still working on my FJ55!

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    Here's the catch can
    [​IMG]

    I'm working on faith here, because my instinct says, "the problem appears to have been fixed, stop screwing with s***!", but you guys know way more about this than i do, so i'm going to stir that hornets nest.

    I'll start by switching the pcv hoses back and see if the problem recurs.

    If it doesn't, i'll talk with the shop about reworking the intake box.

    I'll go to a 4" intake and outlet then necked down to the 2.5" turbo inlet (I think that requires a double boot)
    I'm going to keep the 3" snorkel for the time being and compare with and without the snorkel, before deciding on the 4" snorkel

    Do i need to move the pcv inlet to the air box or is the current location ok?

    Let me know if this is what you guys are suggesting as their have been comments regarding further looking into air intake as well as looking at the fuel system