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DD51T Vacuum Puzzle

Discussion in 'Suzuki Carry' started by rwsem, Jul 2, 2013.

  1. rwsem

    rwsem Member

    Yep, that's it. Looking at the gasket that came off, after spraying carb cleaner, it appears mine was leaking around the port labeled A.
    DSC00908.JPG DSC00920.JPG

    I sealed the plate with High Temp Permatex and will let it cure 24 hours. I'll test it again tomorrow evening.
    Last edited: Jul 6, 2013
  2. spaner

    spaner Well-Known Member

    Cool, keep in mind that aluminum vs steel have very different expansion rates.
    The permatex should make up the difference and will probly be ok.
    Long term, I'd go with an aluminum plate and OEM gasket, but I see your already done.

    FYI, I have 2-coolant nipples that come off the back side. Jim, I see the one you posted only has 1...huh..just when you thought you got them all figured out...
  3. rwsem

    rwsem Member

    Wasn't even thinking past the leak- you are of course correct. If it doesn't seal up, or if it comes loose later, I'll go w/ aluminum and OEM gasket. I was also looking around the backside of my carb. Seems ass though the only adjustments I have to fiddle with are the air/ fuel mix and throttle adjustment on the front side. Everything on the back side, to include the fast idle are not functional. I'm guessing because there is not A/C or automatic trans.
    What's a good starting point of the air/ fuel mix?
  4. spaner

    spaner Well-Known Member

    Cu'z you're not there yet, like the fast idle. The last pic I saw had the vacuum switch, on the left side engine top; disconnected. The backside idle stop..no F port connection.
    Are the parts even there?

    Post a pic..

    Ho yea, that A/F screw is not an A/F screw. It's just a very fine emissions adjustment for CO/NO...
    Won't do nothing for you.
  5. rwsem

    rwsem Member

    I know I don't have an EGR, canister, or TPS. I capped off all the ports on the carb except the choke and distributor. I also capped the "F" thermo/vac EGR switch on the manifold and the port that previously had the distributor run to it (pics 2 and 3 on post #1).
    Pic was too large to upload, here's a link to the backside of the carb:

    I still need info on:
    Where does the F port from the carb run to?
    Do I need a choke delay in the line going to the choke- if so, is it a common part I can pick up in a part store?
    There's a vacuum stem on the back of the air cleaner- what should that be hooked up to, or should I cap it as well?

    Finally- I pulled the distributor cap off to check the contacts- they're all burnt/corroded/trashed. All those parts are Mitzubishi, which I guess is correct for the Suzuki (strange to me...). Must I replace the ignition module at the same time, or only when it stops working?T

    Thanks again for all the guidance guys.
    Last edited: Jul 7, 2013
  6. Jim Nelson

    Jim Nelson Active Member

    The best I can tell you is the pic I posted earlier with the vac lines all intact is pretty close to my other truck which is a '95 but with air and a different set up,apparently,than yours.Your truck has been clobbered up so much I think you will just have to switch things around til you find what works best for you.The most important thing I think is to stop all vac leaks first then start fooling with it to get it the best you can unless of course you want to try to get it all back to original,if you can even figure out what original was.I've never been in to the dizzy farther than caps and rotors,didn't even know they had points.My Scrum has 131,000km and runs like a top so I've never had reason to look into the dizzy.
  7. spaner

    spaner Well-Known Member

    Ho, ha, one at at time dair mang,
    Get some theory, go work on it...
    Come back and get some more. Then read some other stuff. Enjoyment is part of it too, no?

    Choke restrictor, this is so that the butterfly valve moves SLOWLY, independent of engine speed/vacuum pulse, and is not chattering up and down (first stage choke). Also, after an initial start and stall out when cold, wait for 15s, so that the choke has a chance to close back up...ha, see. Have you pulled a vacuum at the actuator to confirm no leaks? How about some Armoral in there, on the rubber? Is it all cracked and spidered?

    Jamb your line onto the nipple first, to make the line bigger.
    Insert small round piece of plastic.
    Drill tiny hole in plastic.
    Re-install line.

    Confirm operation of choke. Adjust choke RPM speed, 2500ish...check complete cycle of choke, look for leaks, check for heat...

    Continue. Otherwise it's pretty hard to help out a jump'en jack rabbit...:p
  8. rwsem

    rwsem Member

    OK, got it- one thing at a time. I just had to fiddle while I was waiting for the permatex to cure. I noticed how crappy the contacts were and there's no doubt I had to replace. I guess I should get a tach too so I know my rpms.

    I haven't pulled vacuum but I should. I guess that could be a cause of surging? I'll head to the parts store tomorrow to purchase a hand vacuum gauge. Any recommendations?
  9. Jim Nelson

    Jim Nelson Active Member

    I like the mity vac unit because it is so versatile, you can check vacuum,bleed brakes,pull a vacuum to check diaphragms or check valves or restricters.pretty handy little kit.Around $30 an Amazon or if you have a Harbor Freight near by they carry them also as well as a China knockoff.
  10. spaner

    spaner Well-Known Member

    Dare you go,

    What I was trying to say, and could have said a little nicer probly, if you go too fast, you're going to miss stuff. You'll just get to the surface of a subject and/or fix and never get really deep into the muck of it.
    Like the choke, wait a minute there...I seem to remember that the nipple on the carb already has a restrictor inside the nipple...:confused:

    Maybe I should pull the green bulb and get back to you to make sure what it actually is.
    Last time I had it off was two years ago.
  11. rwsem

    rwsem Member

    OK... so first- no vacuum leaks around (EGR) plug plate, carb ports, or manifold ports. Choke pulls and maintains vacuum. Truck starts and idles until up to operating temp. Once at operating temp it wants to stall. I can keep it from stalling by closing the choke valve until the engine catches back up. I release the spring tab and the engine runs for a few minutes before it stumbles and wants to die again. Close choke valve and it'll catch back up and I can do this until I tire of it.
    So, now I think the choke needs an adjustment. Don's carb tuning pages point to a choke adjustment screw- should I fiddle with that?

    Picture link shows the screw I'm asking about- it looks like it runs into the thermo wax housing. Also- the screwdriver is on the spring tab that I rotate CCW to keep the engine from stalling.
  12. spaner

    spaner Well-Known Member

    That green bulb is an extreme restrictor. You'd need a leak-down-test on it to confirm flow. Checking it by hand, mouth vacuum, it appears to be blocked at both ends.

    During engine cranking, the choke butterfly valve remains closed.
    After it lights, the choke butterfly takes 2 seconds to open 10 degrees, pauses for 1 second, then opens a further 5 degrees in the 4th second. Engine RPM changes accordingly. 3 distinct RPM phazes.

    At shutdown, the choke butterfly closes very smoothly over a period of 4 seconds.
    Very stable operations.

    I guess that my memory works just fine...:p
  13. spaner

    spaner Well-Known Member

    As to your last update,
    The gizmos should be fixed first before trying any adjustments except base idle.
    You'll just be revisiting the systems every time you find something out of wack and fix it...then adjust again...and again, one more time, then adjust again...

    Hot idle stalling, adjust front idle screw to run at 1500 RPM, at the highest of the variation. Then work on some more bugs...

  14. rwsem

    rwsem Member

    hmm.. my choke valve opens ~90 degrees when at operating temp; fully open, no restriction of air at all- so, that's not right?
    Also- is that green restrictor a common part I can get at a local parts store or should I shop online at a mini truck part site?
  15. spaner

    spaner Well-Known Member

    There are two stages of choke operation. The first is via vacuum control; the mode that I was describing. The second is via push-pin and the water jacket. That post has nothing to do with the second stage choke operation or any choke butterfly angle less than 85%. (100% of choke being closed) from 85% to 0% (90 degrees); second stage/push pin.
    Read this,

  16. rwsem

    rwsem Member

    Thanks, great info- I've bookmarked it for future reference. I'm pretty sure I don't have any problems during startup as it always starts and gets to operating temp. My problems occur after warmup . I was trying to get the idle down to 950-1K so I could verify the timing- guess I can be satisfied at 1500 for now.
  17. spaner

    spaner Well-Known Member

    No worries man,

    It's the details that matter. If you have no idle up system, and you don't, then you need to run at 1500 to take the load of the alt properly. If you had an idle up, you could set to 1000 as the system would be flexable.
    Maybe start a list for missing components and just make an order over the winter; Japan direct.
    The timing, not a huge deal right now, set it for load, with no ping; old school.
    Last edited: Jul 14, 2013
  18. rwsem

    rwsem Member

    Agreed- It's running now and not sucking air, so that in itself is a victory. I'll probably order a fast idle/ idle up system but for now I just need to get it out and run the piss outta it. Maybe I might shake the rest of the gremlins out? Got new Bear Claws coming in TUE and then off to camp next week for a pig hunt, I think.
  19. Jim Nelson

    Jim Nelson Active Member

    I've heard that pig blood runs off all kinds of evil things so that pig hunt is probably a great idea.
    Koyotekiller likes this.
  20. hatch

    hatch Member

    Maybe this has been covered but looking at all the different carb configs, I've seen a lot of different setups. So my question is is it all that important to put the correct vacuum line back to the same barb it came off of on the carb or can it go on any as long as its hooked back up?

    I've seen where some have it going to distrib from a different port than mine. Just curious whether or not it matters or if each carb port does something different.

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