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93 DD51T propane conversion

Discussion in 'Suzuki Carry' started by o8k, Feb 10, 2013.

  1. o8k

    o8k Member

    Make/Model: Suzuki Carry
    Year: 1993
    Engine type: 660cc DD51T
    Project type: Propane conversion

    Synopsys:
    Vehicle idles 1000 times better. It doesnt stink anymore (standing around it while it was idleing was unpleasent). Power feels about the same (it took some adjustments to make that happen). Mind you, I didn’t put this thing on a dyno, im basing this on my top gear acceleration experience. Sadly, I have no choke, cold starts require me to crank the idle mixture screw all the way down for maximum richness. As she warms up, I back it off. Because this engine is really at the very bottom end of volume for the mixer I bought, idle proved to be somewhat tricky. I basically have to lean out the idle mixture to the point that the screw comes out, then a few turns to keep it from vibrating off and falling out.

    Disclaimer

    I don’t know what I’m doing… I don’t know how to work on engines really. I don’t know anything about propane systems either. I would be uneasy just doing a valve lash adjustment or changing a timing belt. However, I like cars I read lots and lots and lots but I have no hands on experience. If you use this information to help yourself and get in a pickle, not my problem! Also, I would be happy to answer questions if you get stuck, but PLEASE don’t ask me something that can be found in this manual if you are gonna attempt this, DON’T unless you get this manual. Use this info at your own risk. Again, I don’t know what im doing. Please offer any advice if you see anything ive done wrong. I’m sharing what I know, im also sharing what I don’t know. Throw me a bone if I could use it…

    *This manual: “IMPCO MATERIAL HANDLING & INDUSTRIAL ENGINE GASEOUS FUEL TRAINING MANUAL”

    Step 1 “The research”
    1. Read other propane conversion posts lots of good info out there.
    2. Use “Google images”, it is your friend.
    3. GET THIS MANUAL!!! “IMPCO MATERIAL HANDLING & INDUSTRIAL ENGINE GASEOUS FUEL TRAINING MANUAL” it’s hard to find a copy but well worth it. After reading this I was able to see lots of stuff that people did WRONG on their propane conversion posts. Also. I would be happy to answer questions if you get stuck, but PLEASE don’t ask me something that can be found in this manual if you are gonna attempt this, DON’T unless you get this manual.

    Examples of how this manual was useful…

    “The fuel regulator must always be lower than the top of the radiator.”
    “Don’t mount it horizontally”
    “Don’t mount it to the engine”

    “it is recommended to use the coolest thermostat allowed by the engine
    manufacturer, preferably 160 degrees”

    “LPG produces higher spark plug temperatures than gasoline.”

    “LPG Ignition timing may be advanced 10% - 20% above the gasoline specification. Initial timing plus centrifugal advance timing should not be more than 28 degrees at 2500 RPM (or max governed no load RPM if less than 2500 RPM). If vacuum advance is used, initial timing plus centrifugal advance timing plus vacuum advance timing should not be more than 45 degrees total advance.”

    “Always follow the engine manufacturer’s recommendations for oil type and change
    intervals. Oil used in gaseous-fueled engines may remain cleaner than oil in gasoline or
    diesel engines but the affects of friction, heat and pressure cause oil to deteriorate and
    even though it looks clean it is worn out.

    “An advantage to using gaseous fuels (LPG, CNG) over liquid fuel (gasoline) is that
    when altitude increases the density of air and gaseous fuels change at about the same
    rate, therefore the air fuel ratio remains unchanged. “

    I don’t want to give everything away so please read the part about the fuel tank features and design, installation criteria, umm… kinda important… if you like living and/or not wasting fuel…

    4. Know your mini truck, buy the service manual, get it from a friend whatever it takes.
    5. Be prepared for the manual to let you down on some very important details like vacuum hoses, coolant circulation and a few other things that I'm still scratching my head on like this…

    [​IMG]


    Step 2 “shopping”

    6. I found a conversion kit on EBAY it was an Impco model 100 mixer and a whopping gigantic Impco Model E fuel regulator. Impco 100 worked out great. The Model E however is way overkill but seems to be working none the less. They guy that sold it to me thought he would be clever and scrape the model numbers off the device but it wasn’t hard to figure out what I had. Kinda pointless for a DYI kit, why confuse your customers unless you plan to include the labor to do the install, how does that work over ebay anyways. Ok the seller must have been confused about a lot of things anyways because im sure what I paid was well under his costs so HA!
    7. EBAY kit I got didn’t come with a throttle body either so I had to buy one. From this guy.

    http://www.usgemini.com/Impco-Throttle-Bodys.html

    US-AT2-4-2 generic. 1-1/4” SAE, 2-15/16” C-C. To top it off, some clown in shipping sent me and identical one w/ a smaller bolt spacing. You can see what I did to fix it from the photos… Also note the port opening on my DD51T is a tad smaller than 1-1/4”.


    Step 3 “Tear Down”

    8. I would recommend labeling EVERYTHING. Just in case, like me, you get distracted by your life and have to put down the project for weeks at a time… (Ok this example is silly, who could forget what that hose is for? But that’s my point. LABEL EVERYTHING no exceptions).

    [​IMG]

    9. Lessons learned, Gasoline is a solvent and will turn cobs of hot glue into slime thus rendering their ability to plug fuel lines useless… <Giggle>

    Step 4 “The install”

    10. I used the heater core to route coolant through the Impco Model E regulator. Another note: The heater core egress and return runs even b/4 the engine reaches tempature and the thermostat opens up. It runs no matter what (presuming your water pump works), kinda nice when your trying to warm up frosty boiling propane.

    This is where it egresses the engine
    [​IMG]

    This is where it enters the radiator.
    [​IMG]

    11. I decided to mount the regulator under the driver’s seat. I really hate this location, im not happy about it but that is where it is. A short hose from regulator to mixer is a good idea, so the manual says. So I made it short. I kinda don’t like a brick of liquid propane being 4” from my ass though.

    [​IMG]

    12. Watch out for vacuum hoses that need to be plugged to avoid rough idle and tuning issues like this little guy…

    [​IMG]

    13. Also, you will see I found the vacuum timing advance hose and plugged it into the throttle body. Not sure if it’s the “right vacuum” but it appears to be working… maybe

    [​IMG]
     
    Last edited: Feb 10, 2013
  2. o8k

    o8k Member

    14. Last but not least the throttle cable, this took some minor fabricating

    Holding the cable housing side like so…
    [​IMG]

    I robbed the old carb of its throttle lever and spring. I had to notch the new throttle body with a grinder and weld the thing on but it worked out great. The gas peddle feels EXACTLY the same as it did b4 which is nice…
    [​IMG]
    [​IMG]

    Of course I had some help through all this…
    [​IMG]

    Well that’s it so far...

    Now for the questions should anyone working on the DD51T may know.

    1. What the devil is this thing? It appears to be coming out of the engine coolant egress but it doesn’t appear to be squirting coolant everywhere…
    [​IMG]

    2. Crank Case ventilation seems to have a vacuum on it. That don’t seem right. Anybody? (UPDATE: not the crank case breather? only goes to the oil cover, why? why suck air through the oil cover? prewarm the air a bit? but but.. <confused>)
    [​IMG]

    3. What is VSV? It was hooked up to my carb and it was sucking air, so I plugged it up… /me shrugs. Vacuum switching valve? For what? Do I need it?
     
    Last edited: Feb 10, 2013
  3. o8k

    o8k Member

    Last but not least... Sorry ive been away so long, life has been bogging me down. It feels nice to be posting again. Hope everyone is doing well, its been a while.
     
    Last edited: Feb 10, 2013
  4. firejonny89

    firejonny89 Member

    Welcome back
     
  5. spaner

    spaner Well-Known Member

    Good for you man, nice to hear back and see the project just truck'en along.
    Tell me you're going to go with a dual fork-lift tank install, under the bed...common, that'd be Sooo cool...dual swapable tanks with gage and remote feed/read switching.
    So, you've been having fun without us...bad, o8K, bad...he, he...

    Yes, we can help you out with a few of those things, be glad to, too, he, he...

    What do you want to start with?


    ...
     
  6. o8k

    o8k Member

    I removed the gas tank today and starting playing with fitment of tanks
    Everything removed out of the rear, looks like this..

    [​IMG]

    My goal is to fit dual tanks on a tray in this space. I have yet to fab up the tray or get the 2nd tank. I think two 33# tanks will fit side by side in there but it will stick out past where my bumper is mounted currently. For now my single tank is just strapped in the back behind the cab. but i really dont want it mounted there permenently b/c it would detract from critical bed space.


    [​IMG]
     
  7. spaner

    spaner Well-Known Member

    Hell, yea....nice man...I've been bored lately...
    You want some help with the mount, or you want to start with the VSV, or just vacuum stuff in general?

    Nice build, very happy for you...;)
     
  8. o8k

    o8k Member

    How about the vacuum hoses and junk... wow, what a maze of hoses...
     
  9. spaner

    spaner Well-Known Member

    Yea, true dat...
    TWO, places for you to start to finish that off,
    First, would be the Dual-VSV system.
    I see that you have the A/C on there, so you'd have the dual controllers. You could just unplug those and make sure that you have a through feed for your rear-diff-lock system, just the single line from the left side of the engine-vacuum port is fine. You'll have to set your base idle though, with both the A/C and head lights-high beam ON...
    She'll idle higher with them both off, but you're not going to mess with those systems, since the carb controller and VSV are gone...
    The second, would be the vacuum controller ports, the items that are left.
    First, I'd get a reading off that single port that you have on the ventury...
    Vacuum @ idle...
    Snap to WOT, what's the reading...
    Then, constant @ 5TRPM...reading...

    Then, with that, we can figure out what to do with the dizzy, EGR, and the Can....
    Cu'z you gott'a run those...


    ...
     
  10. o8k

    o8k Member

    Now that you say it, i think the dual controlers are sitting right on top of the oil cover. Stangely, the engine would not start till i plugged them back in. I havent tried to run my AC yet. I imagine there are two controllers not because they are physically hooked up to the AC but because another is needed to hangle the extra engine load when AC is running at idle.

    <SLAPS SELF> and does his best "DR WHO" i just discovered somthing voice...
    AND THATS WHY... your saying set idle at max load, so the vehicle doesnt stall when i turn on lights/AC etc. b/c i dont have whatever a VSV is (which is obviously for extra engine loads to avoid stalling) ba-da-bing!!!!

    im on a roll.... (edit) NO... your on a roll... im following along...
     
  11. spaner

    spaner Well-Known Member

    Yea, they just flip vacuum around, and, vacuum could be lost, through an open hose (or from load-cu'z no throttle increase-to compensate, that's right)....engine stalls.

    The best solution here, and I like to say now, this is just my opinion, run the left engine port to the rear diff lock, unplug the two electrical connectors...

    Better yet, take e'm right off the engine...a few guys here would love to buy them from you...the carb as well...
     
    Last edited: Feb 10, 2013
  12. o8k

    o8k Member

    Spanner, i must admit, you always seem to inspire me to really learn this stuff. thus, I just found a vacuum diagram from this thread
    http://www.minitrucktalk.com/showthread.php?12911-Desperately-need-tuning-help

    its just a hand drawn sketch but it tells me soooo much, plus the thread has lots of tid-bits worth reading too. I think it would only be fair to read through it b4 i ask much more, i think lots of what i need to know is in there....

    ALso, as soon as i get this thing locked down and running right, i would be happy part with the leftovers. (tho my carb is missing the trottle linkage now b/c i stole it)... Speaking of leftovers, i need to start a thread, "post a pic of all the $H1T you ripped off your mini truck so far" i have a pretty big pile now...

    in case i forgot it in here somewhere... THANKYOU!!!
     
    Last edited: Feb 10, 2013
  13. spaner

    spaner Well-Known Member

    ...


    Yup, no problem at all man.
    You do what you gott'a do and more power to ya.
    You're on the right thread, and it will help you a lot.
    The pou configuration, and just figure that sh!t out...it IS there for you to see.

    Any questions? I'll help you out.

    Love that tank install. MAD MAX SET-UP.
    The rear gate should sit on the tanks. Both of them...:pop:
    A switching service should not be a problem. You figure it out though. Good for you man. I always enjoyed talk'en with you...
    Maybe I can help you out; maybe the point is to do it for yourself...

    What ever you want. I'd be glad to be involved with this build.


    :cool:

    BTW, thanks for the "group join", we'd love to have you in our group...
    ...
     
  14. Wedge

    Wedge Member

    I wonder if a dual setup could be made gas/lpg we had a express van at work that had both it did great mpg. What range do you have on propane 100-150 miles ?
     
  15. o8k

    o8k Member

    Wedge: I donno yet. I have the engine running and i have taken a few test drives up and down the road out here. Thats about it. I considered a dual fuel setup for some time but decided against it. Mainly because i would be required to get it "smogged" for both fuel types which led me to lots of problems i didnt want to deal with. But ironicly, i think by the time im done, i will have to address my issues with that anyways =D
     
  16. o8k

    o8k Member

    ok with vacuum gauge in hand i did some experiments....

    #1 my vacuum advance port appears to be operating as intended, but i was thinking i would get vacuum from that 4 prong'ed thing. What is that 4 prong'ed thing? thanks in advance...

    [​IMG]


    #2 What in the world do i need this vacuum hose for??? If it is just drawing air to the manifold from the oil cover, i dont much see the point. THat only takes away from the vacuum through the throttle body and the LPG mixer. I think i want to plug this up? Please let me know if that is a good/bad idea... thanks....

    [​IMG]


    #3 Here is a pic of my carb, looks like i have a 2+3... I have some more reading to do but i dont think i much need to worry about my CAN or EGR.
    by the way, where is my EGR, i was expecting to see it hanging off the carb. Thanks...
    [​IMG]
     
    Last edited: Feb 13, 2013
  17. Wedge

    Wedge Member

    Thank you for the answer in Canada we dont have emission testing yet... but im thinking a dual fuel would be the best fuel efficient setup as long as you dont have to go through emission tests.
     
  18. spaner

    spaner Well-Known Member

    Wow, OK, so let's start with the right hand side manifold connection tube.
    Do you have any heater hose connections to the air intake?
    NO, I think that you have a stand-alown air filter integal to the LPG fixture.
    The catalitic converter box, and associated hoses have been eliminated, as well as the air-flow-vacuum controller? Right?
    So, that right hand side manifold vacuum nipple, could be sourced for a vacuum gauge. OR, just plug it.
    DONE. Plug it.
     
  19. spaner

    spaner Well-Known Member

    ...


    Man, calm down. You're asking too many questions all at once. A lot of information from you though. Which is good.
    Just Listen,
    OK, #1, "that 4 pronged thing".

    So, check this out...

    [​IMG]


    You see that big red circle that I made?
    That's it. It's a thermal switch. The top two are for the choke controller on the carb. You don't have a carb...OK.
    So de'y not there, which is what you have....Good. Lower side to vacuum, TOP side to EGR controller.
    Put dust caps onto these two connections, so that no dirt gets in there, and you have no switching problems.
    Don't eliminate these, or you'll have problems. Just do it like this.
    EGR, CAN, and Dizzy...
    All go to a tripple T, connected to the single vacuum port at the LPG intake.
    Understand?
    You have the correct vacuum tested, to control the three components. Just hook them up...
    I'll source my graph here, so that you can see...



    carb 2.JPG
     
    Victor Getov likes this.
  20. spaner

    spaner Well-Known Member

  21. spaner

    spaner Well-Known Member

    ...


    OK, # 2 I think, you have to let the block breath, some how. Read up on this on-line. But the best, is what is already there. The PCV valve line; let it do it's thing. The other line; put a fillter on it, and mount it somewhere. This is what I did, and then mounted it right on the rail in the pic...


    [​IMG]



    Caught up yet? Man ask one question at a time, yea?

    ....:confused:

    moto_0146.jpg
     
  22. o8k

    o8k Member

    Ok sorry, yes one at a time.... so here goes, lets start with this one shall we...
    Did some reflecting, tinkering then hooked things up a bit different...
    I hope i got what you were talking about, please conform by reviewing the following pictures.
    Please confirm that i have this right so far, i will just plug up the 4 holes in the thermo vacuum switch
    as soon as i can find somthing proper to plug em with.

    [​IMG]

    Also, please confirm i have a picture of my EGR below...
    [​IMG]
     
    Last edited: Feb 15, 2013
  23. spaner

    spaner Well-Known Member

    Hey sorry man, I come across a little raw sometimes.:sly:

    Yea, looks good to me. Still, I'd run the egr through the two lower connectors on the thermal valve. It's just a switch for when it's cold, should not be connected to the top two. Two switches in the same part. Maybe you don't need it now? You don't have a choke, or cold run system...so..
    I would put it back first, then try with it bypassed later.
    Also, the can...man you got me there..:frustration:

    Right up to this moment, I was like, "well how is the fuel system going to breath?"
    You don't have a gas tank...he, he
    Just had a good laugh.

    I did also want to mention the cable mount. That may ghost on you there with engine vibration. Rubber engine mounts?
    Just a thought. You may not even notice it.
     
  24. o8k

    o8k Member

    0. Yer not coming across raw on this end. No worries, i totally apreciate the help! im learning faster than i can keep up with!!!
    1. Well i dont know if my thermal valve is working for one, i cant get vacuum from it. I could be testing it wrong. Who knows
    2. My emissions test type was changed to Idle test only so i may just bypass the EGR altogether.
    3. I havent had any ghosting yet from my throttle mount, but i never thought of that till you said, ill keep an eye out and move it if needed.

    Ok, umhum, and now for the next question...
    Q1. Where is the crank case breather on my truck? i obviously have two ports on the oil cover (see pictures above) to handle the top end of the engine, but what about the lower end of the engine, the crank case? Is it ported through the block to the oil cover some place or is there a separate hose?
    Crank case breather. Where is it
     
  25. spaner

    spaner Well-Known Member

    Yea, those are them.
    It's a combination of the two hoses.
    You need these. If you mess with these too much, the least that can happen is oil in the distributor cap.
    The worst would be a blown rear main seal.
     
  26. o8k

    o8k Member

    Ok im totally confused. So i get up this morning to put the finishing touches on this thing and i have a problem i dont completely understand.

    Engine starts ok, idles ok, but...
    It stumbles and stalls when i push on the throttle quickly.
    It revs to WOT just fine as long as i go really slowly.

    What did i do =(
     
  27. spaner

    spaner Well-Known Member

    You bypassed the thermal switch for the EGR.
     
  28. spaner

    spaner Well-Known Member

    Explain this a little for you,
    Get the engine really hot, so we can assume the thermal control valve is open,
    You had your carb connection on there, at the base connection of the TCV,
    Then, instead of putting the EGR on to the connector next to it, on the TCV,
    Put your vacuum tester onto this connector on the TCV,

    I bet at some point you have already done this. Right?

    BUT, did you step on the gas? WOT-snap the throttle, remember?
     
  29. o8k

    o8k Member

    AH ha! that explains how i have to test the TCV. I havent done that yet. And I will, but im packin it in for tonight... I tested it without snappin the throttle AND/or i didnt wait for it to get hot <slaps self>

    To help with the confusion, i solved my issue with rev'ing the engine quickly causing stall. Your gonna laugh... the snorkle i put on yesterday was restricting air flow and causing the engine to go so rich it stalled. Ok so now with the snorkel removed all is well again in engine land. So now I can get back to this ERG business.

    So... if i leave the EGR unhooked, wont i get better engine performance? If i understand the EGR correctly, it is only active under vacuum or higher RPMs.
     
  30. spaner

    spaner Well-Known Member

    Well,
    That's just another big can of worms. My understanding is yes, a very small amount, and an decrease in millage...why?

    Read this,

    http://www.tuneruniversity.com/blog/2012/05/dont-block-or-remove-the-egr-valve-its-saving-you-money/

    A few mistakes but that guy has a good understanding of what's really going on with the EGR "system".

    The other side to consider, is the fuel type. LPG, as you know has less power than gas, but your millage should improve with the switch. Experience tells me that you should leave as much as you can to stock. Road test and adjust the LPG set-up, for all it's worth. Then, get the machete out and start chopp'en.

    On the other hand, all things being considered. Whilst chewing peanuts, sipping the green fairy, and tossing the bones...
    I'd say to take it off, clean and test it to make sure that it's not leaking etc, ect...
    Put it back on and block it off.

    So says the fairy...:confused:
     

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